Edgar Filing: BLACKROCK MUNIHOLDINGS INVESTMENT QUALITY FUND

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM N-CSR

CERTIFIED SHAREHOLDER REPORT OF REGISTERED MANAGEMENT INVESTMENT COMPANIES

Investment Company Act file number 811-08349

Name of Fund: BlackRock MuniHoldings Investment Quality Fund (MFL)

Fund Address: 100 Bellevue Parkway, Wilmington, DE 19809

Name and address of agent for service: John M. Perlowski, Chief Executive Officer, BlackRock MuniHoldings Investment Quality Fund, 55 East 52^nd Street, New York, NY 10055

Registrant’s telephone number, including area code: (800) 882-0052, Option 4

Date of fiscal year end: 08/31/2012

Date of reporting period: 02/29/2012

Item 1 – Report to Stockholders


	February 29, 2012

Semi-Annual Report (Unaudited)

BlackRock Municipal Bond Investment Trust (BIE)

BlackRock Municipal Bond Trust (BBK)

BlackRock Municipal Income Investment Quality Trust (BAF)

BlackRock Municipal Income Quality Trust (BYM)

BlackRock Municipal Income Trust II (BLE)

BlackRock MuniHoldings Investment Quality Fund (MFL)

BlackRock MuniVest Fund, Inc. (MVF)

Not FDIC Insured § No Bank Guarantee § May Lose Value

Table of Contents


	Page

Dear Shareholder	3
Semi-Annual Report:
Municipal Market Overview	4
Trust Summaries	5
The Benefits and Risks of Leveraging	12
Derivative Financial Instruments	12
Financial Statements:
Schedules of Investments	13
Statements of Assets and Liabilities	43
Statements of Operations	44
Statements of Changes in Net Assets	45
Statements of Cash Flows	47
Financial Highlights	49
Notes to Financial Statements	56
Officers and Trustees	65
Additional Information	66



2	SEMI-ANNUAL REPORT	FEBRUARY 29, 2012

Dear Shareholder

Risk assets were advancing at this time last year despite a wave of geopolitical revolutions, soaring oil prices and natural disasters in Japan. Markets reversed sharply in May, however, when escalating political strife in Greece rekindled fears about sovereign debt problems spreading across Europe. Concurrently, global economic indicators signaled that the recovery had slowed. Confidence was further shaken by the prolonged debt ceiling debate in Washington, DC. On August 5, 2011, Standard & Poor’s downgraded the US government’s credit rating and turmoil erupted in financial markets around the world. Extraordinary levels of volatility persisted in the months that followed as Greece teetered on the brink of default, debt problems escalated in Italy and Spain, and exposure to European sovereign bonds stressed banks globally. Financial markets whipsawed on hopes and fears. Macro news flow became a greater influence on trading decisions than the fundamentals of the securities traded. By the end of the third quarter, equity markets had fallen nearly 20% from their April peak while safe-haven assets such as US Treasuries and gold had rallied to historic highs.

October brought enough positive economic data to assuage fears of a global double-dip recession. Additionally, European leaders began to show progress toward stemming the region’s debt crisis. Investors began to reenter the markets and risk assets recovered through the month. But a lack of definitive details about Europe’s rescue plan eventually raised doubts among investors and thwarted the rally at the end of October. The last two months of 2011 saw more political instability in Greece, unsustainable yields on Italian government bonds, and US policymakers in gridlock over budget issues. Global central bank actions and improving economic data invigorated the markets, but investor confidence was easily tempered by sobering news flow.

Investors showed more optimism at the start of 2012. Risk assets rallied through January and February as economic data grew stronger and debt problems in Europe stabilized. In the United States, jobs data signaled solid improvement in the labor market and the Federal Reserve indicated that it would keep short-term interest rates low through 2014. In Europe, policymakers made significant progress toward securing a Greek bailout plan and restructuring the nation’s debt. Nevertheless, considerable head-winds remain. Europe faces a prolonged recession, the US economy still remains somewhat shaky and the risks of additional flare ups of euro-zone debt problems and slowing growth in China weigh heavily on the future of the global economy.

Risk assets, including equities and high yield bonds, recovered their late-summer losses and posted strong returns for the 6-month period ended February 29, 2012. On a 12-month basis, US large-cap stocks and high yield bonds delivered positive results, while small-cap and emerging-market stocks finished slightly negative. International markets, which experienced some significant downturns in 2011, lagged the broader rebound. Fixed income securities, which benefited from declining yields, advanced over the 6- and 12-month periods. Despite their quality rating downgrade, US Treasury bonds performed particularly well. Municipal bonds also delivered superior results. Continued low short-term interest rates kept yields on money market securities near their all-time lows.

Many of the themes that caused uncertainty in 2011 remain. For investors, the risks appear daunting, but this challenging environment offers new opportunities. BlackRock was built for these times. Visit blackrock.com/newworld for more information.

Sincerely

-s- Rob Kapito

Rob Kapito
President, BlackRock Advisors, LLC

(PHOTO OF ROB KAPITO)

“For investors, the risks appear daunting, but this challenging environment offers new opportunities. BlackRock was built for these times.”

Rob Kapito
President, BlackRock Advisors, LLC

Total Returns as of February 29, 2012


	6-month		12-month
US large cap equities (S&P 500^®Index)	13.31	%	5.12	%
US small cap equities (Russell 2000^®Index)	12.40		(0.15	)
International equities (MSCI Europe, Australasia, Far East Index)	4.13		(7.45	)
Emerging market equities (MSCI Emerging Markets Index)	5.27		(0.11	)
3-month Treasury bill (BofA Merrill Lynch 3-Month Treasury Bill Index)	0.00		0.08
US Treasury securities (BofA Merrill Lynch 10- Year US Treasury Index)	3.70		17.22
US investment grade bonds (Barclays US Aggregate Bond Index)	2.73		8.37
Tax-exempt municipal bonds (S&P Municipal Bond Index)	5.93		12.88
US high yield bonds (Barclays US Corporate High Yield 2% Issuer Capped Index)	8.62		6.92

Past performance is no guarantee of future results. Index performance is shown for illustrative purposes only. You cannot invest directly in an index.



	THIS PAGE NOT PART OF YOUR FUND REPORT	3

Municipal Market Overview

For the 12-Month Period Ended February 29, 2012

One year ago, the municipal bond market was steadily recovering from a difficult fourth quarter of 2010 that brought severe losses amid a steepening US Treasury yield curve and a flood of inflated headlines about municipal finance troubles. Retail investors had lost confidence in municipals and retreated from the market. Political uncertainty surrounding the midterm elections and tax policies exacerbated the situation. These conditions combined with seasonal illiquidity weakened willful market participation from the trading community. December 2010 brought declining demand with no comparable reduction in supply as issuers rushed their deals to market before the Build America Bond program was retired. This supply-demand imbalance led to wider quality spreads and higher yields for municipal bonds heading into 2011.

(LINE GRAPH)

Demand is usually strong at the beginning of a new year, but retail investors continued to move away from municipal mutual funds in the first half of 2011. From the middle of November 2010, outflows persisted for 29 consecutive weeks, totaling $35.1 billion before the trend finally broke in June 2011. However, weak demand was counterbalanced by lower supply in 2011. According to Thomson Reuters, new issuance was down 32% in 2011 as compared to the prior year. While these technical factors were improving, municipalities were struggling to balance their budgets, although the late-2010 predictions for widespread municipal defaults did not materialize. Other concerns that resonated at the beginning of the year, such as rising interest rates, weakening credits and higher rates of inflation, abated as these scenarios also did not come to fruition.

On August 5, 2011, Standard & Poor’s (“S&P”) downgraded the US government’s credit rating from AAA to AA+. While this led to the downgrade of approximately 11,000 municipal issues directly tied to the US debt rating, this represented a very small fraction of the municipal market and said nothing about the individual municipal credits themselves. In fact, demand for municipal bonds increased as severe volatility in US equities drove investors to more stable asset classes. The municipal market benefited from an exuberant Treasury market and continued muted new issuance. As supply remained constrained, demand from both traditional and non-traditional buyers was strong, pushing long-term municipal bond yields lower and sparking a curve-flattening trend that continued through year end. Ultimately, 2011 was one of the strongest performance years in municipal market history. The S&P Municipal Bond Index returned 10.62% in 2011, making municipal bonds a top-performing fixed income asset class for the year.

Market technicals often begin a new year quite strong, only to moderate by the end of February as increasing supply begins to satisfy demand. This theme remained intact for 2012. Overall, the municipal yield curve flattened during the period from February 28, 2011 to February 29, 2012. As measured by Thomson Municipal Market Data, yields declined by 146 basis points (“bps”) to 3.23% on AAA-rated 30-year municipal bonds and by 112 bps to 1.85% on 10-year bonds, while yields on 5-year issues fell 108 bps to 0.68%. While the entire municipal curve flattened over the 12-month time period, the spread between 2- and 30-year maturities tightened by 101 bps, and in the 2- to 10-year range, the spread tightened by 67 bps.

The fundamental picture for municipalities continues to improve. Austerity has been the general theme across the country, while a small number of states continue to rely on a “kick-the-can” approach to close their budget shortfalls, with aggressive revenue projections and accounting gimmicks. It has been over a year since the first highly publicized interview about the fiscal problems plaguing state and local governments. Thus far, the prophecy of widespread defaults across the municipal market has not materialized. In 2011, there were fewer municipal defaults than seen in 2010. Throughout 2011 monetary defaults in the S&P Municipal Bond Index totaled roughly $805 million, representing less than 0.48% of the index. BlackRock maintains the view that municipal bond defaults will remain in the periphery and the overall market is fundamentally sound. We continue to recognize that careful credit research and security selection remain imperative amid uncertainty in this economic environment.

Past performance is no guarantee of future results. Index performance is shown for illustrative purposes only. You cannot invest directly in an index.



4	SEMI-ANNUAL REPORT	FEBRUARY 29, 2012



Trust Summary as of February 29, 2012	BlackRock Municipal Bond Investment Trust


Trust Overview

BlackRock Municipal Bond Investment Trust’s (BIE) (the “Trust”) investment objective is to provide current income exempt from regular federal income tax and Florida intangible personal property tax. The Trust seeks to achieve its investment objective by investing primarily in municipal bonds exempt from federal income taxes (except that the interest may be subject to the federal alternative minimum tax). Under normal market conditions, the Trust invests at least 80% of its assets in municipal bonds that are investment grade quality at the time of investment. The Trust may invest directly in such securities or synthetically through the use of derivatives.

	No assurance can be given that the Trust’s investment objective will be achieved.

Performance

For the six months ended February 29, 2012, the Trust returned 17.53% based on market price and 13.50% based on net asset value (“NAV”). For the same period, the closed-end Lipper General & Insured Municipal Debt Funds (Leveraged) category posted an average return of 14.97% based on market price and 11.83% based on NAV. All returns reflect reinvestment of dividends. The Trust moved from a discount to NAV to a premium by period end, which accounts for the difference between performance based on price and performance based on NAV. The following discussion relates to performance based on NAV. As the yield curve flattened during the period (longer-term interest rates fell more than shorter-term rates), rising bond prices in the long end of the municipal curve contributed positively to the Trust’s performance. The Trust’s longer-dated holdings in the health, transportation and education sectors experienced the strongest price appreciation.

	The views expressed reflect the opinions of BlackRock as of the date of this report and are subject to change based on changes in market, economic or other conditions. These views are not intended to be a forecast of future events and are no guarantee of future results.

Trust Information


Symbol on New York Stock Exchange (“NYSE”)	BIE
Initial Offering Date	April 30, 2002
Yield on Closing Market Price as of February 29, 2012 ($16.19)¹	6.00%
Tax Equivalent Yield²	9.23%
Current Monthly Distribution per Common Share³	$0.0810
Current Annualized Distribution per Common Share³	$0.9720
Economic Leverage as of February 29, 2012⁴	38%


	¹	Yield on closing market price is calculated by dividing the current annualized distribution per share by the closing market price. Past performance does not guarantee future results.

	²	Tax equivalent yield assumes the maximum federal tax rate of 35%.

	³	The distribution rate is not constant and is subject to change.

	⁴	Represents Variable Rate Demand Preferred Shares (“VRDP Shares”) and tender option bond trusts (“TOBs”) as a percentage of total managed assets, which is the total assets of the Trust, including any assets attributable to VRDP Shares and TOBs, minus the sum of accrued liabilities. For a discussion of leveraging techniques utilized by the Trust, please see The Benefits and Risks of Leveraging on page 12.

The table below summarizes the changes in the Trust’s market price and NAV per share:


	2/29/12	8/31/11	Change	High	Low
Market Price	$16.19	$14.22	13.85%	$16.60	$14.18
Net Asset Value	$16.13	$14.67	9.95%	$16.19	$14.67

The following charts show the sector and credit quality allocations of the Trust’s long-term investments:


Sector Allocations
	2/29/12		8/31/11
Transportation	21	%	21	%
County/City/Special District/School District	21		17
Utilities	17		19
Health	15		23
State	10		6
Education	9		7
Housing	5		5
Corporate	1		1
Tobacco	1		1

Credit Quality Allocations⁵

	2/29/12		8/31/11
AAA/Aaa	11	%	10	%
AA/Aa	64		62
A	19		21
BBB/Baa	5		6
BB/Ba	—		1
Not Rated	1		—


	⁵	Using the higher of Standard & Poor’s (“S&P’s”) or Moody’s Investors Service (“Moody’s”) ratings.



SEMI-ANNUAL REPORT	FEBRUARY 29, 2012	5



Trust Summary as of February 29, 2012	BlackRock Municipal Bond Trust

Trust Overview

BlackRock Municipal Bond Trust’s (BBK) (the “Trust”) investment objective is to provide current income exempt from regular federal income tax. The Trust seeks to achieve its investment objective by investing primarily in municipal bonds exempt from regular federal income taxes (except that the interest may be subject to the federal alternative minimum tax). The Trust invests, under normal market conditions, at least 80% of its assets in municipal bonds that are investment grade quality. The Trust may invest directly in such securities or synthetically through the use of derivatives.


	No assurance can be given that the Trust’s investment objective will be achieved.

Performance
For the six months ended February 29, 2012, the Trust returned 17.13% based on market price and 14.84% based on NAV. For the same period, the closed-end Lipper General & Insured Municipal Debt Funds (Leveraged) category posted an average return of 14.97% based on market price and 11.83% based on NAV. All returns reflect reinvestment of dividends. The Trust’s premium to NAV, which widened during the period, accounts for the difference between performance based on price and performance based on NAV. The following discussion relates to performance based on NAV. During the period, the Trust benefited from the declining interest rate environment (bond prices rise when interest rates fall), the flattening of the yield curve (long-term interest rates fell more than short and intermediate rates) and tightening of credit spreads. The Trust’s exposure to zero-coupon bonds and the health sector had a significant impact on performance as these holdings derived the greatest benefit from the decline in interest rates and spread tightening during the period.

	The views expressed reflect the opinions of BlackRock as of the date of this report and are subject to change based on changes in market, economic or other conditions. These views are not intended to be a forecast of future events and are no guarantee of future results.

Trust Information


Symbol on NYSE	BBK
Initial Offering Date	April 30, 2002
Yield on Closing Market Price as of February 29, 2012 ($16.81)¹	6.32%
Tax Equivalent Yield²	9.72%
Current Monthly Distribution per Common Share³	$0.0885
Current Annualized Distribution per Common Share³	$1.0620
Economic Leverage as of February 29, 2012⁴	35%


	¹	Yield on closing market price is calculated by dividing the current annualized distribution per share by the closing market price. Past performance does not guarantee future results.

	²	Tax equivalent yield assumes the maximum federal tax rate of 35%.

	³	The distribution rate is not constant and is subject to change.

	⁴	Represents Variable Rate Muni Term Preferred Shares (“VMTP Shares”) and TOBs as a percentage of total managed assets, which is the total assets of the Trust, including any assets attributable to VMTP Shares and TOBs, minus the sum of accrued liabilities. For a discussion of leveraging techniques utilized by the Trust, please see The Benefits and Risks of Leveraging on page 12.

The table below summarizes the changes in the Trust’s market price and NAV per share:


	2/29/12	8/31/11	Change	High	Low
Market Price	$16.81	$14.86	13.12%	$17.44	$14.80
Net Asset Value	$16.06	$14.48	10.91%	$16.10	$14.48

The following charts show the sector and credit quality allocations of the Trust’s long-term investments:


Sector Allocations

	2/29/12			8/31/11
Health		20	%		21	%
State		15			14
Education		13			10
County/City/Special District/School District		13			12
Transportation		12			10
Housing		10			14
Corporate		9			10
Utilities		5			7
Tobacco		3			2


Credit Quality Allocations⁵

	2/29/12			8/31/11
AAA/Aaa		6	%		11	%
AA/Aa		39			35
A		25			18
BBB/Baa		18			22
BB/Ba		5			1
B		1			6
CCC/Caa		—			1
Not Rated⁶		6			6


	⁵	Using the higher of S&P’s or Moody’s ratings.

	⁶	The investment advisor has deemed certain of these non-rated securities to be of investment grade quality. As of February 29, 2012 and August 31, 2011, the market value of these securities was $3,120,455, representing 1%, and $4,646,558, representing 2%, respectively, of the Trust’s long-term investments.



6	SEMI-ANNUAL REPORT	FEBRUARY 29, 2012



Trust Summary as of February 29, 2012	BlackRock Municipal Income Investment Quality Trust

Trust Overview

BlackRock Municipal Income Investment Quality Trust’s (BAF) (the “Trust”) investment objective is to provide current income exempt from federal income tax, including the alternative minimum tax and Florida intangible property tax. The Trust seeks to achieve its investment objective by investing, under normal circumstances, at least 80% of its assets in municipal bonds exempt from federal income taxes, including the alternative minimum tax. The Trust also invests at least 80% of its assets in municipal bonds that are investment grade quality at the time of investment. The Trust may invest directly in such securities or synthetically through the use of derivatives.


	No assurance can be given that the Trust’s investment objective will be achieved.


Performance

For the six months ended February 29, 2012, the Trust returned 16.65% based on market price and 13.40% based on NAV. For the same period, the closed-end Lipper General & Insured Municipal Debt Funds (Leveraged) category posted an average return of 14.97% based on market price and 11.83% based on NAV. All returns reflect reinvestment of dividends. The Trust’s discount to NAV, which narrowed during the period, accounts for the difference between performance based on price and performance based on NAV. The following discussion relates to performance based on NAV. As the yield curve flattened during the period (longer-term interest rates fell more than shorter-term rates), rising bond prices in the long end of the municipal curve contributed positively to the Trust’s performance. The Trust’s longer-dated holdings in the health, transportation and education sectors experienced the strongest price appreciation.

	The views expressed reflect the opinions of BlackRock as of the date of this report and are subject to change based on changes in market, economic or other conditions. These views are not intended to be a forecast of future events and are no guarantee of future results.

Trust Information


Symbol on NYSE	BAF
Initial Offering Date	October 31, 2002
Yield on Closing Market Price as of February 29, 2012 ($15.76)¹	5.67%
Tax Equivalent Yield²	8.72%
Current Monthly Distribution per Common Share³	$0.0745
Current Annualized Distribution per Common Share³	$0.8940
Economic Leverage as of February 29, 2012⁴	35%


	¹	Yield on closing market price is calculated by dividing the current annualized distribution per share by the closing market price. Past performance does not guarantee future results.

	²	Tax equivalent yield assumes the maximum federal tax rate of 35%.

	³	The distribution rate is not constant and is subject to change.

	⁴	Represents VMTP Shares and TOBs as a percentage of total managed assets, which is the total assets of the Trust, including any assets attributable to VMTP Shares and TOBs, minus the sum of accrued liabilities. For a discussion of leveraging techniques utilized by the Trust, please see The Benefits and Risks of Leveraging on page 12.

The table below summarizes the changes in the Trust’s market price and NAV per share:


	2/29/12	8/31/11	Change	High	Low
Market Price	$15.76	$13.92	13.22%	$16.17	$13.76
Net Asset Value	$15.96	$14.50	10.07%	$16.01	$14.50

The following charts show the sector and credit quality allocations of the Trust’s long-term investments:


Sector Allocations

	2/29/12			8/31/11
County/City/Special District/School District		29	%		34	%
Utilities		29			22
Transportation		17			16
Health		11			9
Education		6			9
State		6			8
Housing		1			1
Tobacco		1			1

Credit Quality Allocations⁵

	2/29/12			8/31/11
AAA/Aaa		7	%		14	%
AA/Aa		78			70
A		14			12
BBB/Baa		1			4


	⁵	Using the higher of S&P’s or Moody’s ratings.



SEMI-ANNUAL REPORT	FEBRUARY 29, 2012	7



Trust Summary as of February 29, 2012	BlackRock Municipal Income Quality Trust

Trust Overview

BlackRock Municipal Income Quality Trust’s (BYM) (the “Trust”) investment objective is to provide current income exempt from federal income taxes, including the alternative minimum tax. The Trust seeks to achieve its investment objective by investing, under normal circumstances, at least 80% of its assets in municipal bonds exempt from federal income taxes, including the alternative minimum tax. The Trust also invests at least 80% of its assets in municipal bonds that are investment grade quality at the time of investment. The Trust may invest directly in such securities or synthetically through the use of derivatives.


	No assurance can be given that the Trust’s investment objective will be achieved.


Performance

For the six months ended February 29, 2012, the Trust returned 17.33% based on market price and 13.28% based on NAV. For the same period, the closed-end Lipper General & Insured Municipal Debt Funds (Leveraged) category posted an average return of 14.97% based on market price and 11.83% based on NAV. All returns reflect reinvestment of dividends. The Trust moved from a discount to NAV to a premium by period end, which accounts for the difference between performance based on price and performance based on NAV. The following discussion relates to performance based on NAV. During the period, the Trust benefited from the declining interest rate environment (bond prices rise when interest rates fall), the flattening of the yield curve (long-term interest rates fell more than short and intermediate rates) and tightening of credit spreads. The Trust’s exposure to zero-coupon bonds and the health sector had a positive impact on performance as these holdings derived the greatest benefit from the decline in interest rates and spread tightening during the period.

	The views expressed reflect the opinions of BlackRock as of the date of this report and are subject to change based on changes in market, economic or other conditions. These views are not intended to be a forecast of future events and are no guarantee of future results.


Trust Information


Symbol on NYSE	BYM
Initial Offering Date	October 31, 2002
Yield on Closing Market Price as of February 29, 2012 ($15.75)¹	5.87%
Tax Equivalent Yield²	9.03%
Current Monthly Distribution per Common Share³	$0.0770
Current Annualized Distribution per Common Share³	$0.9240
Economic Leverage as of February 29, 2012⁴	36%


	¹	Yield on closing market price is calculated by dividing the current annualized distribution per share by the closing market price. Past performance does not guarantee future results.

	²	Tax equivalent yield assumes the maximum federal tax rate of 35%.

	³	The Monthly Distribution per Common Share, declared on March 1, 2012, was increased to $0.0780 per share. The Yield on Closing Market Price, Current Monthly Distribution per Common Share and Current Annualized Distribution per Common Share do not reflect the new distribution rate. The new distribution rate is not constant and is subject to change in the future.

	⁴	Represents VMTP Shares and TOBs as a percentage of total managed assets, which is the total assets of the Trust, including any assets attributable to VMTP Shares and TOBs, minus the sum of accrued liabilities. For a discussion of leveraging techniques utilized by the Trust, please see The Benefits and Risks of Leveraging on page 12.

The table below summarizes the changes in the Trust’s market price and NAV per share:


	2/29/12	8/31/11	Change	High	Low
Market Price	$15.75	$13.85	13.72%	$15.86	$13.76
Net Asset Value	$15.47	$14.09	9.79%	$15.52	$14.09

The following charts show the sector and credit quality allocations of the Trust’s long-term investments:


Sector Allocations

	2/29/12			8/31/11
Transportation		23	%		24	%
County/City/Special District/School District		20			18
Utilities		18			21
State		15			14
Health		9			8
Education		6			6
Tobacco		5			6
Corporate		3			2
Housing		1			1

Credit Quality Allocations⁵

	2/29/12			8/31/11
AAA/Aaa		28	%		21	%
AA/Aa		49			58
A		14			13
BBB/Baa		9			8


	⁵	Using the higher of S&P’s or Moody’s ratings.



8	SEMI-ANNUAL REPORT	FEBRUARY 29, 2012




Trust Summary as of February 29, 2012	BlackRock Municipal Income Trust II

Trust Overview

BlackRock Municipal Income Trust II’s (BLE) (the “Trust”) investment objective is to provide current income exempt from regular federal income tax. The Trust seeks to achieve its investment objective by investing primarily in municipal bonds exempt from federal income taxes (except that the interest may be subject to the federal alternative minimum tax). The Trust invests, under normal market conditions, at least 80% of its assets in municipal bonds that are investment grade quality at the time of investment. The Trust may invest directly in such securities or synthetically through the use of derivatives.


	No assurance can be given that the Trust’s investment objective will be achieved.

Performance

For the six months ended February 29, 2012, the Trust returned 15.47% based on market price and 13.99% based on NAV. For the same period, the closed-end Lipper General & Insured Municipal Debt Funds (Leveraged) category posted an average return of 14.97% based on market price and 11.83% based on NAV. All returns reflect reinvestment of dividends. The Trust’s premium to NAV, which widened during the period, accounts for the difference between performance based on price and performance based on NAV. The following discussion relates to performance based on NAV. Among contributing factors, the most significant were the Trust’s duration profile (sensitivity to interest rate movements) and yield curve positioning, both of which were designed to benefit in an environment where interest rates moved broadly lower and, more specifically, where long-term municipal yields decline relative to short-term yields. Security selection and sector allocation also provided meaningful contributions to the Trust’s performance. Most notably, the Trust’s holdings in transportation, health and tobacco boosted returns as these sectors outperformed the broader market during the period. The Trust’s investments in local municipalities and school districts within the tax-backed sector were a modest drag on returns as these segments tended to underperform the overall market.


	The views expressed reflect the opinions of BlackRock as of the date of this report and are subject to change based on changes in market, economic or other conditions. These views are not intended to be a forecast of future events and are no guarantee of future results.

Trust Information


Symbol on NYSE Amex		BLE
Initial Offering Date		July 30, 2002
Yield on Closing Market Price as of February 29, 2012 ($15.77)¹		6.35%
Tax Equivalent Yield²		9.77%
Current Monthly Distribution per Common Share³	$	0.0835
Current Annualized Distribution per Common Share³	$	1.0020
Economic Leverage as of February 29, 2012⁴		38%


	¹	Yield on closing market price is calculated by dividing the current annualized distribution per share by the closing market price. Past performance does not guarantee future results.

	²	Tax equivalent yield assumes the maximum federal tax rate of 35%.

	³	The Monthly Distribution per Common Share, declared on March 1, 2012, was increased to $0.0850 per share. The Yield on Closing Market Price, Current Monthly Distribution per Common Share and Current Annualized Distribution per Common Share do not reflect the new distribution rate. The new distribution rate is not constant and is subject to change in the future.

	⁴	Represents VMTP Shares and TOBs as a percentage of total managed assets, which is the total assets of the Trust, including any assets attributable to VMTP Shares and TOBs, minus the sum of accrued liabilities. For a discussion of leveraging techniques utilized by the Trust, please see The Benefits and Risks of Leveraging on page 12.

The table below summarizes the changes in the Trust’s market price and NAV per share:



	2/29/12		8/31/11		Change		High		Low
Market Price	$	15.77	$	14.13		11.61%	$	16.05	$	13.85
Net Asset Value	$	15.38	$	13.96		10.17%	$	15.40	$	13.96

The following charts show the sector and credit quality allocations of the Trust’s long-term investments:



Sector Allocations
	2/29/12			8/31/11
Health		19	%		21	%
Transportation		17			13
State		16			16
Utilities		14			13
Corporate		9			10
County/City/Special District		9			10
Education		8			8
Tobacco		5			4
Housing		3			5



Credit Quality Allocations⁵
	2/29/12			8/31/11
AAA/Aaa		10	%		10	%
AA/Aa		34			32
A		27			26
BBB/Baa		17			16
BB/Ba		2			5
B		3			4
Not Rated⁶		7			7


	⁵	Using the higher of S&P’s or Moody’s ratings.

	⁶	The investment advisor has deemed certain of these non-rated securities to be of investment grade quality. As of February 29, 2012 and August 31, 2011, the market value of these securities was $15,304,944, representing 3%, and $11,677,703, representing 2%, respectively, of the Trust’s long-term investments.



SEMI-ANNUAL REPORT	FEBRUARY 29, 2012	9




Trust Summary as of February 29, 2012	BlackRock MuniHoldings Investment Quality Fund

Trust Overview

BlackRock MuniHoldings Investment Quality Fund’s (MFL) (the “Trust”) investment objective is to provide shareholders with current income exempt from federal income tax and to provide shareholders with the opportunity to own shares the value of which is exempt from Florida intangible personal property tax. The Trust seeks to achieve its investment objective by investing primarily in long-term, investment grade municipal obligations exempt from federal income taxes (except that the interest may be subject to the federal alternative minimum tax). Under normal market conditions, the Trust invests at least 80% of its assets in municipal obligations with remaining maturities of one year or more at the time of investment. The Trust may invest directly in such securities or synthetically through the use of derivatives.

No assurance can be given that the Trust’s investment objective will be achieved.

Performance

For the six months ended February 29, 2012, the Trust returned 14.18% based on market price and 13.02% based on NAV. For the same period, the closed-end Lipper General & Insured Municipal Debt Funds (Leveraged) category posted an average return of 14.97% based on market price and 11.83% based on NAV. All returns reflect reinvestment of dividends. The Fund’s discount to NAV, which narrowed during the period, accounts for the difference between performance based on price and performance based on NAV. The following discussion relates to performance based on NAV. As the yield curve flattened during the period (longer-term interest rates fell more than shorter-term rates), rising bond prices in the long end of the municipal curve contributed positively to the Trust’s performance. The Trust’s longer-dated holdings in the health, transportation and education sectors experienced the strongest price appreciation.


	The views expressed reflect the opinions of BlackRock as of the date of this report and are subject to change based on changes in market, economic or other conditions. These views are not intended to be a forecast of future events and are no guarantee of future results.



Trust Information
Symbol on NYSE			MFL
Initial Offering Date			September 26, 1997
Yield on Closing Market Price as of February 29, 2012 ($15.31)¹			6.00%
Tax Equivalent Yield²			9.23%
Current Monthly Distribution per Common Share³			$0.0765
Current Annualized Distribution per Common Share³			$0.9180
Economic Leverage as of February 29, 2012⁴			39%


	¹	Yield on closing market price is calculated by dividing the current annualized distribution per share by the closing market price. Past performance does not guarantee future results.

	²	Tax equivalent yield assumes the maximum federal tax rate of 35%.

	³	The distribution rate is not constant and is subject to change.

	⁴	Represents VRDP Shares and TOBs as a percentage of total managed assets, which is the total assets of the Trust, including any assets attributable to VRDP Shares and TOBs, minus the sum of accrued liabilities. For a discussion of leveraging techniques utilized by the Trust, please see The Benefits and Risks of Leveraging on page 12.

The table below summarizes the changes in the Trust’s market price and NAV per share:



	2/29/12		8/31/11		Change		High		Low
Market Price	$	15.31	$	13.84		10.62%	$	15.39	$	13.20
Net Asset Value	$	15.33	$	14.00		9.50%	$	15.40	$	14.00

The following charts show the sector and credit quality allocations of the Trust’s long-term investments:



Sector Allocations
	2/29/12			8/31/11
Transportation		24	%		25	%
Utilities		21			25
County/City/Special District/School District		21			18
State		11			10
Health		10			11
Education		9			6
Housing		3			4
Tobacco		1			1



Credit Quality Allocations⁵
	2/29/12			8/31/11
AAA/Aaa		9	%		12	%
AA/Aa		76			72
A		14			12
BBB/Baa		1			2
Not Rated⁶		—			2


	⁵	Using the higher of S&P’s or Moody’s ratings.

	⁶	The investment advisor has deemed certain of these non-rated securities to be of investment grade quality. As of February 29, 2012 and August 31, 2011, the market value of these securities was $1,114,020 and $3,979,631, each representing less than 1%, respectively, of the Trust’s long-term investments.



10	SEMI-ANNUAL REPORT	FEBRUARY 29, 2012




Trust Summary as of February 29, 2012	BlackRock MuniVest Fund, Inc.

Trust Overview

BlackRock MuniVest Fund, Inc.’s (MVF) (the “Trust”) investment objective is to provide shareholders with as high a level of current income exempt from federal income taxes as is consistent with its investment policies and prudent investment management. The Trust seeks to achieve its investment objective by investing at least 80% of its assets in municipal obligations exempt from federal income taxes (except that the interest may be subject to the federal alternative minimum tax). The Trust invests, under normal market conditions, primarily in long term municipal obligations rated investment grade at the time of investment and invests primarily in long term municipal obligations with maturities of more than ten years at the time of investment. The Trust may invest directly in such securities or synthetically through the use of derivatives.

No assurance can be given that the Trust’s investment objective will be achieved.

Performance

For the six months ended February 29, 2012, the Trust returned 14.27% based on market price and 11.65% based on NAV. For the same period, the closed-end Lipper General & Insured Municipal Debt Funds (Leveraged) category posted an average return of 14.97% based on market price and 11.83% based on NAV. All returns reflect reinvestment of dividends. The Fund’s premium to NAV, which widened during the period, accounts for the difference between performance based on price and performance based on NAV. The following discussion relates to performance based on NAV. During the period, municipal bond prices generally rose as the yield curve flattened (longer-term interest rates fell more than shorter-term rates) and credit spreads tightened. Given these market conditions, the Fund’s exposure to longer-maturity bonds and lower-quality investment grade bonds had a significant positive impact on the Fund’s performance. The Fund’s exposure to zero-coupon bonds and the health sector also boosted returns as these types of bonds derived the greatest benefit from the decline in interest rates and spread tightening during the period.


	The views expressed reflect the opinions of BlackRock as of the date of this report and are subject to change based on changes in market, economic or other conditions. These views are not intended to be a forecast of future events and are no guarantee of future results.



Trust Information
Symbol on NYSE Amex		MVF
Initial Offering Date	September 29, 1988
Yield on Closing Market Price as of February 29, 2012 ($10.73)¹		6.60%
Tax Equivalent Yield²		10.15%
Current Monthly Distribution per Common Share³	$	0.0590
Current Annualized Distribution per Common Share³	$	0.7080
Economic Leverage as of February 29, 2012⁴		40%


	¹	Yield on closing market price is calculated by dividing the current annualized distribution per share by the closing market price. Past performance does not guarantee future results.

	²	Tax equivalent yield assumes the maximum federal tax rate of 35%.

	³	The distribution rate is not constant and is subject to change.

	⁴	Represents VMTP Shares and TOBs as a percentage of total managed assets, which is the total assets of the Trust, including any assets attributable to VMTP Shares and TOBs, minus the sum of accrued liabilities. For a discussion of leveraging techniques utilized by the Trust, please see The Benefits and Risks of Leveraging on page 12.

The table below summarizes the changes in the Trust’s market price and NAV per share:



	2/29/12		8/31/11		Change		High		Low
Market Price	$	10.73	$	9.73		10.28%	$	10.99	$	9.63
Net Asset Value	$	10.29	$	9.55		7.75%	$	10.32	$	9.55

The following charts show the sector and credit quality allocations of the Trust’s long-term investments:



Sector Allocations
	2/29/12			8/31/11
Health		23	%		23	%
Transportation		19			17
Corporate		12			13
Utilities		12			12
County/City/Special District/School District		9			9
Education		9			9
State		8			8
Housing		6			7
Tobacco		2			2



Credit Quality Allocations⁵
	2/29/12	8/31/11
AAA/Aaa	12%	12%
AA/Aa	47	46
A	24	22
BBB/Baa	14	15
BB/Ba	—	1
B	1	1
Not Rated⁶	2	3


	⁵	Using the higher of S&P’s or Moody’s ratings.

	⁶	The investment advisor has deemed certain of these non-rated securities to be of investment grade quality. As of February 29, 2012 and August 31, 2011, the market value of these securities was $19,911,457 and $22,724,541, each representing2%, respectively, of the Trust’s long-term investments.



SEMI-ANNUAL REPORT	FEBRUARY 29, 2012	11

The Benefits and Risks of Leveraging

The Trusts may utilize leverage to seek to enhance the yield and NAV of their common shares (“Common Shares”). However, these objectives cannot be achieved in all interest rate environments.

To obtain leverage, the Trusts issue Variable Rate Demand Preferred Shares (“VRDP Shares”) or Variable Rate Muni Term Preferred Shares (“VMTP Shares”) and previously issued and had outstanding Auction Market Preferred Shares (“AMPS”) (VRDP Shares, VMTP Shares, and as applicable AMPS, are collectively referred to as “Preferred Shares”). Preferred Shares pay dividends at prevailing short-term interest rates, and the Trusts invest the proceeds in long-term municipal bonds. In general, the concept of leveraging is based on the premise that the financing cost of assets to be obtained from leverage, which will be based on short-term interest rates, will normally be lower than the income earned by each Trust on its longer-term portfolio investments. To the extent that the total assets of each Trust (including the assets obtained from leverage) are invested in higher-yielding portfolio investments, each Trust’s shareholders will benefit from the incremental net income.

To illustrate these concepts, assume a Trust’s Common Shares capitalization is $100 million and it issues Preferred Shares for an additional $50 million, creating a total value of $150 million available for investment in long-term municipal bonds. If prevailing short-term interest rates are 3% and long-term interest rates are 6%, the yield curve has a strongly positive slope. In this case, the Trust pays dividends on the $50 million of Preferred Shares based on the lower short-term interest rates.At the same time, the securities purchased by the Trust with assets received from Preferred Shares issuance earn income based on long-term interest rates. In this case, the dividends paid to holders of Preferred Shares (“Preferred Shareholders”) are significantly lower than the income earned on the Trust’s long-term investments, and therefore the Common Shareholders are the beneficiaries of the incremental net income.

If short-term interest rates rise, narrowing the differential between short-term and long-term interest rates, the incremental net income pickup will be reduced or eliminated completely. Furthermore, if prevailing short-term interest rates rise above long-term interest rates, the yield curve has a negative slope. In this case, the Trust pays higher short-term interest rates whereas the Trust’s total portfolio earns income based on lower long-term interest rates.

Furthermore, the value of the Trusts’ portfolio investments generally varies inversely with the direction of long-term interest rates, although other factors can influence the value of portfolio investments. In contrast, the redemption value of the Trusts’ Preferred Shares and/or debt securities does not fluctuate in relation to interest rates. As a result, changes in interest rates can influence the Trusts’ NAVs positively or negatively in addition to the impact on Trust performance from leverage from Preferred Shares and borrowings discussed above.

The Trusts may also leverage their assets through the use of tender option bond trusts (“TOBs”), as described in Note 1 of the Notes to Financial Statements. TOB investments generally will provide the Trusts with economic benefits in periods of declining short-term interest rates, but expose the Trusts to risks during periods of rising short-term interest rates similar to those associated with Preferred Shares issued by the Trusts, as described above. Additionally, fluctuations in the market value of municipal bonds deposited into the TOB trust may adversely affect each Trust’s NAV per share.

The use of leverage may enhance opportunities for increased income to the Trusts and Common Shareholders, but as described above, it also creates risks as short- or long-term interest rates fluctuate. Leverage also will generally cause greater changes in the Trusts’ NAVs, market prices and dividend rates than comparable portfolios without leverage. If the income derived from securities purchased with assets received from leverage exceeds the cost of leverage, the Trusts’ net income will be greater than if leverage had not been used. Conversely, if the income from the securities purchased is not sufficient to cover the cost of leverage, each Trust’s net income will be less than if leverage had not been used, and therefore the amount available for distribution to Common Shareholders will be reduced. Each Trust may be required to sell portfolio securities at inopportune times or at distressed values in order to comply with regulatory requirements applicable to the use of leverage or as required by the terms of leverage instruments, which may cause a Trust to incur losses. The use of leverage may limit each Trust’s ability to invest in certain types of securities or use certain types of hedging strategies, such as in the case of certain restrictions imposed by rating agencies that rate the Preferred Shares issued by the Trusts. Each Trust will incur expenses in connection with the use of leverage, all of which are borne by the Common Shareholders and may reduce income to the Common Shares.

Under the Investment Company Act of 1940, as amended (the “1940 Act”), the Trusts are permitted to issue senior securities in the form of equity securities (e.g., Preferred Shares) up to 50% of their total managed assets (each Trust’s net assets plus the proceeds of any outstanding borrowings). In addition, each Trust voluntarily limits its economic leverage to 45% of its total managed assets for Trusts with VRDP Shares or VMTP Shares. As of February 29, 2012, the Trusts had economic leverage from Preferred Shares and/or TOBs as a percentage of their total managed assets as follows:


	Percent of Economic Leverage
BIE	38%
BBK	35%
BAF	35%
BYM	36%
BLE	38%
MFL	39%
MVF	40%

Derivative Financial Instruments

The Trusts may invest in various derivative financial instruments, including financial futures contracts, as specified in Note 2 of the Notes to Financial Statements, which may constitute forms of economic leverage. Such derivative financial instruments are used to obtain exposure to a market without owning or taking physical custody of securities or to hedge market and/or interest rate risks. Derivative financial instruments involve risks, including the imperfect correlation between the value of a derivative financial instrument and the underlying asset, possible default of the counterparty to the transaction or illiquidity of the derivative financial instrument. The Trusts’ ability to use a derivative financial instrument successfully depends on the investment advisor’s ability to predict pertinent market movements accurately, which cannot be assured. The use of derivative financial instruments may result in losses greater than if they had not been used, may require a Trust to sell or purchase portfolio investments at inopportune times or for distressed values, may limit the amount of appreciation a Trust can realize on an investment, may result in lower dividends paid to shareholders or may cause a Trust to hold an investment that it might otherwise sell. The Trusts’ investments in these instruments are discussed in detail in the Notes to Financial Statements.



12	SEMI-ANNUAL REPORT	FEBRUARY 29, 2012



Schedule of Investments February 29, 2012 (Unaudited)	BlackRock Municipal Bond Investment Trust (BIE)
Schedule of Investments February 29, 2012 (Unaudited)	(Percentages shown are based on Net Assets)


Municipal Bonds	Par (000)		Value
Alabama — 0.3%
Selma IDB, RB, International Paper Co. Project, Series A, 5.38%, 12/01/35	$	145	$	151,883
Alaska — 0.3%
Northern Tobacco Securitization Corp., RB, Asset-Backed Series A, 5.00%, 6/01/46		180		131,441
California — 10.6%
California Educational Facilities Authority, RB, University of Southern California, Series A, 5.25%, 10/01/38		700		798,672
California Health Facilities Financing Authority, RB, Scripps Health, Series A, 5.00%, 11/15/40		90		97,782
California Health Facilities Financing Authority, Refunding RB, Catholic Healthcare West, Series A, 6.00%, 7/01/39		120		137,341
Grossmont Union High School District, GO, Election of 2008, Series B, 4.75%, 8/01/45		950		998,412
Los Angeles Department of Water & Power, RB, Power System, Sub-Series A-1, 5.25%, 7/01/38		1,660		1,892,782
San Diego Regional Building Authority California, RB, County Operations Center & Annex, Series A, 5.38%, 2/01/36		850		943,067
State of California, GO, Various Purpose, 6.00%, 3/01/33		685		820,048
				5,688,104
Colorado — 1.2%
Colorado Health Facilities Authority, Refunding RB, Catholic Healthcare, Series A, 5.50%, 7/01/34		580		640,256
Delaware — 1.3%
County of Sussex Delaware, RB, NRG Energy, Inc., Indian River Project, 6.00%, 10/01/40		655		705,468
District of Columbia — 1.4%
District of Columbia Water & Sewer Authority, RB, Series A, 5.25%, 10/01/29		640		747,418
Florida — 1.7%
Orange County Health Facilities Authority, RB, The Nemours Foundation Project, Series A, 5.00%, 1/01/29		415		453,076
Village Community Development District No. 9, RB, Special Assessment Revenue, 5.25%, 5/01/31		475		480,491
				933,567


Municipal Bonds	Par (000)		Value
Georgia — 1.2%
Municipal Electric Authority of Georgia, Refunding RB, Project One, Sub-Series D, 6.00%, 1/01/23	$	555	$	667,837
Illinois — 11.7%
Chicago Board of Education Illinois, GO, Series A:
5.50%, 12/01/39		500		566,100
5.00%, 12/01/41		565		609,285
Chicago Transit Authority, RB, Sales Tax Receipts Revenue, 5.25%, 12/01/36		165		183,629
City of Chicago Illinois, RB:
O’Hare International Airport Revenue, General, Third Lien, Series C, (AGM), 6.50%, 1/01/41		1,590		1,913,629
Sales Tax Revenue, Series A, 5.25%, 1/01/38		205		229,737
Illinois Finance Authority, RB:
Carle Foundation, Series A, 6.00%, 8/15/41		750		823,162
Navistar International, Recovery Zone, 6.50%, 10/15/40		270		289,478
Northwestern Memorial Hospital, 6.00%, 8/15/39		1,000		1,148,040
Railsplitter Tobacco Settlement Authority, RB:
5.50%, 6/01/23		365		420,400
6.00%, 6/01/28		105		117,482
				6,300,942
Indiana — 5.4%
Indiana Finance Authority Wastewater Utility, RB, First Lien, CWA Authority Project, Series A, 5.25%, 10/01/31		770		880,965
Indiana Municipal Power Agency, RB, Series B, 6.00%, 1/01/39		1,190		1,353,208
Indianapolis Local Public Improvement Bond Bank, RB, Series K (AGM), 5.00%, 6/01/25		605		688,599
				2,922,772
Iowa — 0.2%
Iowa Tobacco Settlement Authority, RB, Asset-Backed, Series C, 5.63%, 6/01/46		140		107,930
Kansas — 1.9%
Kansas Development Finance Authority, Refunding RB, Adventist Health, 5.50%, 11/15/29		900		1,038,420
Kentucky — 3.8%
Kentucky Economic Development Finance Authority, RB, Owensboro Medical Health System, Series A, 6.38%, 6/01/40		350		392,501

Portfolio Abbreviations

To simplify the listings of portfolio holdings in the Schedules of Investments, the names and descriptions of many of the securities have been abbreviated according to the following list:


AGC	Assured Guaranty Corp.
AGM	Assured Guaranty Municipal Corp.
AMBAC	American Municipal Bond Assurance Corp.
AMT	Alternative Minimum Tax (subject to)
BHAC	Berkshire Hathaway Assurance Corp.
CAB	Capital Appreciation Bonds
CIFG	CDC IXIS Financial Guaranty
COP	Certificates of Participation
EDA	Economic Development Authority
EDC	Economic Development Corp.
ERB	Education Revenue Bonds
FGIC	Financial Guaranty Insurance Co.
FHA	Federal Housing Administration
GARB	General Airport Revenue Bonds
GO	General Obligation Bonds
HDA	Housing Development Authority
HFA	Housing Finance Agency
HRB	Housing Revenue Bonds
IDA	Industrial Development Authority
IDB	Industrial Development Board
ISD	Independent School District
MRB	Mortgage Revenue Bonds
NPFGC	National Public Finance Guarantee Corp.
PSF-GTD	Permanent School Fund Guaranteed
Q-SBLF	Qualified School Bond Loan Fund
RB	Revenue Bonds
S/F	Single Family
SBPA	Stand-by Purchase Agreement
VRDN	Variable Rate Demand Notes


See Notes to Financial Statements.

	SEMI-ANNUAL REPORT	FEBRUARY 29, 2012	13



Schedule of Investments (continued)	BlackRock Municipal Bond Investment Trust (BIE)
Schedule of Investments (continued)	(Percentages shown are based on Net Assets)


Municipal Bonds	Par (000)		Value
Kentucky (concluded)
Louisville & Jefferson County Metropolitan Government, RB, Jewish Hospital & St. Mary’s HealthCare, 6.13%, 2/01/37	$	675	$	723,114
Louisville & Jefferson County Metropolitan Government Parking Authority, RB, Series A, 5.75%, 12/01/34		800		928,360
				2,043,975
Louisiana — 0.8%
Louisiana Local Government Environmental Facilities & Community Development Authority, RB, Westlake Chemical Corp., Series A-1, 6.50%, 11/01/35		380		424,498
Maine — 1.5%
Maine Health & Higher Educational Facilities Authority, RB, Maine General Medical Center, 7.50%, 7/01/32		675		776,763
Massachusetts — 1.3%
Massachusetts Development Finance Agency, Refunding RB, Trustees of Deerfield Academy, 5.00%, 10/01/40		375		427,144
Massachusetts State College Building Authority, RB, Series A, 5.50%, 5/01/39		250		279,777
				706,921
Michigan — 3.4%
Lansing Board of Water & Light, RB, Series A, 5.50%, 7/01/41		485		561,678
Michigan State Building Authority, Refunding RB, Facilities Program, Series I, 6.00%, 10/15/38		500		570,175
Royal Oak Hospital Finance Authority Michigan, Refunding RB, William Beaumont Hospital, 8.25%, 9/01/39		530		667,599
				1,799,452
Multi-State — 6.1%
Centerline Equity Issuer Trust, 7.20%, 11/15/52 (a)(b)		3,000		3,274,380
Nevada — 7.9%
City of Las Vegas Nevada, GO, Limited Tax, Performing Arts Center, 6.00%, 4/01/34		1,000		1,162,530
County of Clark Nevada, RB:
Motor Vehicle Fuel Tax, 5.00%, 7/01/28		1,130		1,265,193
Series B, 5.75%, 7/01/42		1,630		1,827,214
				4,254,937
New Jersey — 7.1%
New Jersey EDA, Refunding RB, School Facilities Construction, Series AA, 5.50%, 12/15/29		750		850,433
New Jersey State Housing & Mortgage Finance Agency, RB, S/F Housing, Series CC, 5.25%, 10/01/29		620		665,818
New Jersey Transportation Trust Fund Authority, RB, Transportation System:
Series A, 5.88%, 12/15/38		695		794,906
Series A, 5.50%, 6/15/41		500		571,055
Series B, 5.25%, 6/15/36		850		952,068
				3,834,280
New York — 6.9%
Hudson New York Yards Infrastructure Corp., RB, Series A, 5.75%, 2/15/47		145		163,833
New York City Transitional Finance Authority, RB:
Building Aid, Sub-Series 1A, 5.25%, 7/15/37		1,000		1,130,290
Fiscal 2009, Series S-3, 5.25%, 1/15/39		1,000		1,098,420
New York Liberty Development Corp., Refunding RB, Second Priority, Bank of America Tower at One Bryant Park Project, 6.38%, 7/15/49		325		352,680
Triborough Bridge & Tunnel Authority, RB, General, Series A-2, 5.38%, 11/15/38		840		952,770
				3,697,993


Municipal Bonds	Par (000)		Value
Pennsylvania — 8.1%
Pennsylvania Economic Development Financing Authority, RB, American Water Co. Project, 6.20%, 4/01/39	$	300	$	346,380
Pennsylvania Turnpike Commission, RB:
Sub-Series A, 5.63%, 12/01/31		1,000		1,135,580
Sub-Series A, 6.00%, 12/01/41		1,500		1,663,440
Sub-Series C (AGC), 6.25%, 6/01/38		500		594,895
Philadelphia Hospitals & Higher Education Facilities Authority, RB, Children’s Hospital of Philadelphia, Series D, 5.00%, 7/01/32		575		635,939
				4,376,234
Texas — 12.0%
Central Texas Regional Mobility Authority, RB, Senior Lien, 6.00%, 1/01/41		890		954,863
Conroe ISD Texas, GO, School Building, Series A, 5.75%, 2/15/35		470		573,499
Harris County Cultural Education Facilities Finance Corp., RB, Texas Children’s Hospital Project, 5.25%, 10/01/29		340		387,607
Harris County Health Facilities Development Corp., Refunding RB, Memorial Hermann Healthcare System, Series B, 7.13%, 12/01/31		250		301,412
Lamar Texas Consolidated Independent School District, GO, Refunding RB, Schoolhouse Improvements, Series A, 5.00%, 2/15/45 (c)		350		395,083
North Texas Tollway Authority, RB, Special Projects System, Series A, 5.50%, 9/01/41		900		1,035,837
North Texas Tollway Authority, Refunding RB, System, First Tier, Series K-1 (AGC), 5.75%, 1/01/38		250		279,743
Tarrant County Cultural Education Facilities Finance Corp., RB, Scott & White Healthcare, 6.00%, 8/15/45		1,020		1,165,982
Texas Private Activity Bond Surface Transportation Corp., RB, Senior Lien, NTE Mobility Partners LLC, North Tarrant Express Managed Lanes Project, 6.88%, 12/31/39		500		566,705
University of Texas System, Refunding RB, Financing System Bonds, Series B, 5.00%, 8/15/43 (c)		715		820,420
				6,481,151
Virginia — 1.6%
Virginia Public School Authority, RB, School Financing, 6.50%, 12/01/35		750		882,300
Washington — 3.7%
Port of Seattle, Refunding RB, Intermediate Lien, Series A, 5.00%, 8/01/32 (c)		1,000		1,137,520
University of Washington, Refunding, RB, Series A, 5.00%, 7/01/41 (c)		730		829,703
				1,967,223
Wisconsin — 1.8%
Wisconsin Health & Educational Facilities Authority, RB, Froedtert & Community Health, 5.25%, 4/01/39		890		962,615
Total Municipal Bonds — 103.2%				55,518,760


See Notes to Financial Statements.

14	SEMI-ANNUAL REPORT	FEBRUARY 29, 2012



Schedule of Investments (continued)	BlackRock Municipal Bond Investment Trust (BIE)
Schedule of Investments (continued)	(Percentages shown are based on Net Assets)


Municipal Bonds Transferred to Tender Option Bond Trusts (d)	Par (000)		Value
California — 19.3%
California Educational Facilities Authority, RB, University of Southern California, Series A, 5.25%, 10/01/39	$	1,005	$	1,133,489
Grossmont Union High School District, GO, Election of 2008, Series B, 5.00%, 8/01/40		1,300		1,419,340
Los Angeles Community College District California, GO, Election of 2008:
Series A, 6.00%, 8/01/33		2,079		2,482,119
Series C, 5.25%, 8/01/39		1,410		1,616,283
Los Angeles Unified School District California, GO, Series I, 5.00%, 1/01/34		200		221,030
San Diego Public Facilities Financing Authority, Refunding RB, Series B, 5.50%, 8/01/39		2,234		2,571,339
University of California, RB, Series O, 5.75%, 5/15/34		810		947,141
				10,390,741
District of Columbia — 3.5%
District of Columbia, RB, Series A, 5.50%, 12/01/30		735		879,810
District of Columbia Water & Sewer Authority, RB, Series A, 5.50%, 10/01/39		899		1,016,294
				1,896,104
Illinois — 7.4%
Illinois Finance Authority, RB, University of Chicago, Series B, 6.25%, 7/01/38		1,500		1,773,735
Illinois State Toll Highway Authority, RB, Series B, 5.50%, 1/01/33		2,000		2,190,333
				3,964,068
Massachusetts — 1.6%
Massachusetts School Building Authority, RB, Senior Lien, Series B, 5.00%, 10/15/41		790		886,807
Nevada — 3.2%
Clark County Water Reclamation District, GO, Limited Tax, 6.00%, 7/01/38		1,500		1,743,840
New Hampshire — 1.2%
New Hampshire Health & Education Facilities Authority, Refunding RB, Dartmouth College, 5.25%, 6/01/39		585		664,618
New Jersey — 2.0%
New Jersey Transportation Trust Fund Authority, RB, Transportation System, Series A (AGM), 5.00%, 12/15/32		1,000		1,079,640
New York — 9.7%
New York City Municipal Water Finance Authority, RB:
Fiscal 2009, Series A, 5.75%, 6/15/40		750		870,539
Series FF-2, 5.50%, 6/15/40		990		1,141,631
New York State Dormitory Authority, ERB, Series B, 5.25%, 3/15/38		1,000		1,111,700
New York State Liberty Development Corp., RB, 1 World Trade Center Project, 5.25%, 12/15/43		1,170		1,312,681
New York State Liberty Development Corp., Refunding RB, 4 World Trade Center Project, 5.75%, 11/15/51		680		772,596
				5,209,147
Ohio — 1.7%
County of Allen Ohio, Refunding RB, Catholic Healthcare, Series A, 5.25%, 6/01/38		840		894,902
Puerto Rico — 1.0%
Puerto Rico Sales Tax Financing Corp., RB, Sales Tax Revenue, Series C, 5.25%, 8/01/40		460		510,858
South Carolina — 2.1%
South Carolina State Public Service Authority, RB, Santee Cooper, Series A, 5.50%, 1/01/38		1,005		1,138,665


Municipal Bonds Transferred to Tender Option Bond Trusts (d)	Par (000)		Value
Texas — 5.2%
City of San Antonio Texas, Refunding RB, Series A, 5.25%, 2/01/31	$	1,050	$	1,205,613
Harris County Cultural Education Facilities Finance Corp., RB, Hospital, Texas Children’s Hospital Project, 5.50%, 10/01/39		1,450		1,616,199
				2,821,812
Virginia — 1.0%
Fairfax County IDA Virginia, Refunding RB, Health Care, Inova Health System, Series A, 5.50%, 5/15/35		460		512,868
Total Municipal Bonds Transferred to Tender Option Bond Trusts — 58.9%				31,714,070
Total Long-Term Investments (Cost — $78,705,048) — 162.1%				87,232,830


Short-Term Securities	Shares
FFI Institutional Tax-Exempt Fund, 0.01% (e)(f)		3,025,425		3,025,425
Total Short-Term Securities (Cost — $3,025,425) — 5.6%				3,025,425
Total Investments (Cost — $81,730,473) — 167.7%				90,258,255
Liabilities in Excess of Other Assets — (5.2)%				(2,808,624	)
Liability for TOB Trust Certificates, Including Interest Expense and Fees Payable — (29.4)%				(15,825,594	)
VRDP Shares, at Liquidation Value — (33.1)%				(17,800,000	)
Net Assets Applicable to Common Shares — 100.0%			$	53,824,037


(a)	Security represents a beneficial interest in a trust. The collateral deposited into the trust is federally tax-exempt revenue bonds issued by various state or local governments, or their respective agencies or authorities. The security is subject to remarketing prior to its stated maturity.

(b)	Security exempt from registration pursuant to Rule 144A under the Securities Act of 1933. These securities may be resold in transactions exempt from registration to qualified institutional investors.

(c)	When-issued security. Unsettled when-issued transactions were as follows:


Counterparty	Value		Unrealized Appreciation
Barclays Capital Inc.	$	829,703	$	5,606
JPMorgan Securities	$	1,137,520	$	3,280
Morgan Keegan & Co.	$	395,083	$	1,491
Morgan Stanley Co.	$	820,420	$	7,279


(d)	Securities represent bonds transferred to a TOB in exchange for which the Trust acquired residual interest certificates. These securities serve as collateral in a financing transaction. See Note 1 of the Notes to Financial Statements for details of municipal bonds transferred to TOBs.

(e)	Investments in companies considered to be an affiliate of the Trust during the period, for purposes of Section 2(a)(3) of the Investment Company Act of 1940, as amended, were as follows:


Affiliate	Shares Held at August 31, 2011	Net Activity	Shares Held at February 29, 2012		Income
FFI Institutional Tax-Exempt Fund	2,198,525	826,900	3,025,425	$	231


(f)	Represents the current yield as of report date.


See Notes to Financial Statements.

	SEMI-ANNUAL REPORT	FEBRUARY 29, 2012	15




Schedule of Investments (concluded)	BlackRock Municipal Bond Investment Trust (BIE)
Schedule of Investments (concluded)


•	Financial futures contracts sold as of February 29, 2012 were as follows:

Contracts

Issue

Exchange

Expiration

Notional
Value

Unrealized
Depreciation

10-Year US

Chicago

March

2,362,781

(13,815)

Treasury Note

Board of Trade

2012


•	Fair Value Measurements — Various inputs are used in determining the fair value of investments and derivative financial instruments. These inputs are categorized into a disclosure hierarchy consisting of three broad levels for financial statement purposes as follows:

	•	Level 1 — unadjusted price quotations in active markets/exchanges for identical assets and liabilities

	•	Level 2 — other observable inputs (including, but not limited to: quoted prices for similar assets or liabilities in markets that are active, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the assets or liabilities (such as interest rates, yield curves, volatilities, prepayment speeds, loss severities, credit risks and default rates) or other market-corroborated inputs)

	•	Level 3 — unobservable inputs based on the best information available in the circumstances, to the extent observable inputs are not available (including the Trust’s own assumptions used in determining the fair value of investments and derivative financial instruments)

	Changes in valuation techniques may result in transfers in or out of an assigned level within the disclosure hierarchy. The categorization of a value determined for investments and derivative financial instruments is based on the pricing transparency of the investment and derivative financial instrument and does not necessarily correspond to the Trust’s perceived risk of investing in those securities. For information about the Trust’s policy regarding valuation of investments and derivative financial instruments and other significant accounting policies, please refer to Note 1 of the Notes to Financial Statements.

	The following tables summarize the inputs used as of February 29, 2012 in determining the fair valuation of the Trust’s investments and derivative financial instruments:


Valuation Inputs	Level 1		Level 2		Level 3		Total
Assets:
Investments:
Long-Term Investments¹		—	$	87,232,830		—	$	87,232,830
Short-Term Securities	$	3,025,425		—		—		3,025,425
Total	$	3,025,425	$	87,232,830		—	$	90,258,255


	¹	See above Schedule of Investments for values in each state or political subdivision.


Valuation Inputs	Level 1			Level 2		Level 3		Total
Derivative Financial
Instruments²
Liabilities:
Interest rate contracts	$	(13,815	)		—		—	$	(13,815	)


	²	Derivative financial instruments are financial futures contracts, which are valued at the unrealized appreciation/depreciation on the instrument.


See Notes to Financial Statements.

16	SEMI-ANNUAL REPORT	FEBRUARY 29, 2012




Schedule of Investments February 29, 2012 (Unaudited)	BlackRock Municipal Bond Trust (BBK)
Schedule of Investments February 29, 2012 (Unaudited)	(Percentages shown are based on Net Assets)


Municipal Bonds	Par (000)		Value
Alabama — 4.1%
Birmingham Special Care Facilities Financing Authority, RB, Children’s Hospital (AGC):
6.00%, 6/01/34	$	1,150	$	1,321,614
6.00%, 6/01/39		450		514,256
Birmingham Water Works Board, RB, 4.75%, 1/01/36		2,100		2,214,597
Hoover City Board of Education, GO, Refunding, 4.25%, 2/15/40		2,750		2,857,277
				6,907,744
Arizona — 8.4%
Arizona Sports & Tourism Authority, RB, Multipurpose Stadium Facilities, Series A (NPFGC), 5.00%, 7/01/31		1,750		1,764,315
Arizona State University, RB, Series D, 5.50%, 7/01/26		200		240,894
County of Pinal Arizona Election District No. 3, Refunding RB, 4.75%, 7/01/31		3,750		3,955,237
Mohave County Unified School District No. 20 Kingman, GO, School Improvement Project of 2006, Series C (AGC), 5.00%, 7/01/26		200		225,954
Pima County IDA, Refunding IRDB, Tucson Electric Power, 5.75%, 9/01/29		900		940,212
Salt Verde Financial Corp., RB, Senior:
5.00%, 12/01/32		1,500		1,509,540
5.00%, 12/01/37		2,065		2,064,835
San Luis Facility Development Corp., RB, Senior Lien, Regional Detention Center Project:
6.25%, 5/01/15		245		240,597
7.00%, 5/01/20		300		300,513
7.25%, 5/01/27		600		553,608
State of Arizona, COP, Department of Administration, Series A (AGM), 5.00%, 10/01/29		750		821,768
University Medical Center Corp. Arizona, RB:
6.00%, 7/01/39		900		996,165
6.50%, 7/01/39		500		566,885
				14,180,523
California — 17.9%
California County Tobacco Securitization Agency, RB, CAB, Stanislaus, Sub-Series C, 6.30%, 6/01/55 (a)		4,500		52,470
California Educational Facilities Authority, RB, Santa Clara University, 5.00%, 2/01/40		1,000		1,092,120
California Health Facilities Financing Authority, Refunding RB, Sutter Health, Series B, 5.88%, 8/15/31		1,900		2,249,353
California HFA, RB, Home Mortgage, Series G, AMT, 5.05%, 2/01/29		2,285		2,194,468
Carlsbad Unified School District, GO, Election of 2006, Series B, 6.09%, 5/01/34 (b)		1,000		741,600
City of San Jose California, RB, San Jose Airport, Series A1, AMT, 5.75%, 3/01/34		2,000		2,206,800
Dinuba Unified School District, GO, Election of 2006 (AGM):
5.63%, 8/01/31		250		286,740
5.75%, 8/01/33		500		576,135
Hartnell Community College District California, GO, CAB, Election of 2002, Series D, 7.46%, 8/01/34 (b)		1,650		1,089,611
Norwalk-La Mirada Unified School District California, GO, CAB, Election of 2002, Series E (AGC), 6.47%, 8/01/38 (a)		8,000		1,873,600
Palomar Community College District, GO, CAB, Election of 2006, Series B:
6.09%, 8/01/30 (a)		1,500		614,865
6.15%, 8/01/33 (a)		4,000		1,100,040
6.44%, 8/01/39 (b)		2,000		1,066,180
San Diego Community College District California, GO, CAB, Election of 2002, 6.24%, 8/01/19 (b)		2,800		2,095,772


Municipal Bonds	Par (000)		Value
California (concluded)
San Jose Evergreen Community College District, GO, Election of 2010, Series B, 3.50%, 8/01/32	$	1,200	$	1,165,788
State of California, GO, Various Purpose:
5.75%, 4/01/31		2,000		2,330,760
6.00%, 3/01/33		1,000		1,197,150
6.50%, 4/01/33		1,950		2,398,246
5.50%, 3/01/40		2,350		2,604,716
State of California, GO, Refunding:
(CIFG), 4.50%, 8/01/28		500		523,335
Veterans, AMT, 5.05%, 12/01/36		1,000		1,015,200
Val Verde Unified School District California, Special Tax Bonds, Refunding, Junior Lien, 6.25%, 10/01/28		1,585		1,616,431
				30,091,380
Colorado — 1.2%
Colorado Health Facilities Authority, RB, Catholic Health Initiatives, Series D, 6.25%, 10/01/33		1,070		1,241,767
Park Creek Metropolitan District, Refunding RB, Limited Property Tax (AGM), 6.00%, 12/01/38		750		850,350
				2,092,117
Connecticut — 2.3%
Connecticut State Health & Educational Facilities Authority, RB:
Hartford Healthcare, Series A, 5.00%, 7/01/32		1,390		1,491,762
Lawrence & Memorial Hospital, Series F, 5.00%, 7/01/36		1,100		1,163,855
Sacred Heart University, Series G, 5.38%, 7/01/31		400		435,976
Western Connecticut Health, Series M, 5.38%, 7/01/41		700		762,391
				3,853,984
Delaware — 0.8%
County of Sussex Delaware, RB, NRG Energy, Inc., Indian River Project, 6.00%, 10/01/40		1,200		1,292,460
District of Columbia — 1.5%
District of Columbia Tobacco Settlement Financing Corp., Refunding RB, Asset-Backed, 6.75%, 5/15/40		2,500		2,521,325
Florida — 6.1%
County of Lee Florida, Refunding RB, Lee Airport, Series A, AMT (AGM), 5.00%, 10/01/28		2,000		2,141,580
Palm Beach County Housing Finance Authority, HRB, Indian Trace Apartments, Series A, AMT (AGM), 5.63%, 1/01/44		7,255		7,259,643
Stevens Plantation Community Development District, Special Assessment Bonds, Series A, 7.10%, 5/01/35		925		791,338
				10,192,561
Idaho — 1.2%
Idaho Health Facilities Authority, Refunding RB, Trinity Health Group, Series B, 6.25%, 12/01/33		1,750		2,066,033
Illinois — 7.5%
Chicago Transit Authority, RB, 5.25%, 12/01/40		665		738,369
Illinois Finance Authority, RB:
MJH Education Assistance IV LLC, Sub-Series B, 5.38%, 6/01/35 (c)(d)		425		42,500
Navistar International, Recovery Zone, 6.50%, 10/15/40		1,285		1,377,700
Roosevelt University Project, 6.50%, 4/01/44		1,000		1,086,480
Rush University Medical Center, Series C, 6.63%, 11/01/39		650		770,569
Illinois Finance Authority, Refunding RB, Series A:
Friendship Village Schaumburg, 5.63%, 2/15/37		210		180,655
OSF Healthcare System, 6.00%, 5/15/39		1,040		1,164,966
Railsplitter Tobacco Settlement Authority, RB:
6.25%, 6/01/24		1,000		1,114,910
6.00%, 6/01/28		1,150		1,286,712


See Notes to Financial Statements.
	SEMI-ANNUAL REPORT	FEBRUARY 29, 2012	17




Schedule of Investments (continued)	BlackRock Municipal Bond Trust (BBK)
Schedule of Investments (continued)	(Percentages shown are based on Net Assets)


Municipal Bonds	Par (000)		Value
Illinois (concluded)
Village of Bolingbrook Illinois, GO, Refunding, Series B (NPFGC), 6.23%, 1/01/36 (a)	$	21,065	$	4,858,221
				12,621,082
Indiana — 1.9%
Indiana Finance Authority, Refunding RB:
5.25%, 10/01/38		2,000		2,226,060
Improvement, U.S. Steel Corp., 6.00%, 12/01/26		1,000		1,020,090
				3,246,150
Iowa — 1.5%
Iowa Higher Education Loan Authority, RB, Private College Facility, Buena Vista University Project, 5.00%, 4/01/31		875		951,528
Iowa Higher Education Loan Authority, Refunding RB, Private College Facility:
5.75%, 9/01/30		500		536,460
6.00%, 9/01/39		1,000		1,049,030
				2,537,018
Louisiana — 2.5%
Jefferson Parish Hospital Service District No. 1, Refunding RB, West Jefferson Medical Center, Series A (AGM), 6.00%, 1/01/39		1,450		1,610,428
Louisiana Local Government Environmental Facilities & Community Development Authority, RB, Westlake Chemical Corp, Series A-1, 6.50%, 11/01/35		1,050		1,172,955
Louisiana Public Facilities Authority, RB, Belle Chasse Educational Foundation Project, 6.50%, 5/01/31		400		433,872
Louisiana Public Facilities Authority, Refunding RB, Entergy Gulf States Louisiana, LLC Project, Series A, 5.00%, 9/01/28		1,000		1,049,080
				4,266,335
Maryland — 1.9%
Maryland EDC, Refunding RB, CNX Marine Terminals, Inc., 5.75%, 9/01/25		250		259,597
Maryland Health & Higher Educational Facilities Authority, Refunding RB, Doctor’s Community Hospital, 5.63%, 7/01/30		2,900		3,010,113
				3,269,710
Michigan — 3.4%
Michigan State Building Authority, Refunding RB, Facilities Program, Series I, 6.25%, 10/15/38		1,250		1,444,113
Royal Oak Hospital Finance Authority Michigan, Refunding RB, William Beaumont Hospital, 8.25%, 9/01/39		1,950		2,456,259
Wayne County Airport Authority, Refunding RB, Airport Revenue, Series A (AGM), 4.00%, 12/01/20		1,750		1,813,682
				5,714,054
Minnesota — 4.3%
City of Minneapolis Minnesota, Refunding RB, Fairview Health Services, Series B (AGC), 6.50%, 11/15/38		5,350		6,291,760
Tobacco Securitization Authority Minnesota, Refunding RB, Tobacco Settlement, Series B, 5.25%, 3/01/31		800		870,088
				7,161,848
Mississippi — 3.4%
Mississippi Development Bank, RB, Hinds Community College District, CAB (AGM), 5.00%, 4/01/36		845		916,876
Mississippi Development Bank Special Obligation, RB, Jackson County Limited Tax Note (AGC), 5.50%, 7/01/32		1,750		1,965,075
University of Southern Mississippi, RB, Campus Facilities Improvements Project, 5.38%, 9/01/36		2,100		2,347,653


Municipal Bonds	Par (000)		Value
Mississippi (concluded)
Warren County Mississippi, RB, Gulf Opportunity Zone Bonds (International Paper Company Project), Series A, AMT, 5.38%, 12/01/35	$	400	$	419,308
				5,648,912
Missouri — 1.7%
Missouri State Development Finance Board, RB, St. Joseph Sewage System Improvements, 5.25%, 5/01/31		580		611,053
Missouri State Health & Educational Facilities Authority, RB:
A.T. Still University Health Sciences, 5.25%, 10/01/31		500		542,300
A.T. Still University Health Sciences, 5.25%, 10/01/41		650		693,869
Lutheran Senior Services, 6.00%, 2/01/41		1,000		1,069,000
				2,916,222
Montana — 0.8%
Montana Facility Finance Authority, Refunding RB, Sisters of Leavenworth, Series A, 4.75%, 1/01/40		1,350		1,431,473
Multi-State — 6.8%
Centerline Equity Issuer Trust, 7.20%, 11/15/52 (e)(f)		10,500		11,460,330
Nebraska — 2.3%
Nebraska Investment Finance Authority, Refunding RB, Series A, 6.05%, 9/01/41		990		1,054,172
Omaha Nebraska Sanitation Sewer Revenue, RB, System:
4.25%, 11/15/38		1,890		1,978,792
4.25%, 11/15/41		775		808,185
				3,841,149
Nevada — 1.1%
City of Las Vegas Nevada, Special Assessment Bonds, Summerlin Area, 5.65%, 6/01/23		1,295		1,218,763
County of Clark Nevada, Refunding RB, Alexander Dawson School Nevada Project, 5.00%, 5/15/29		575		602,497
				1,821,260
New Jersey — 14.2%
Middlesex County Improvement Authority, RB, Subordinate, Heldrich Center Hotel, Series B, 6.25%, 1/01/37 (c)(d)		915		81,893
New Jersey EDA, RB:
Cigarette Tax, 5.50%, 6/15/24		3,710		3,730,553
Continental Airlines Inc. Project, AMT, 7.20%, 11/15/30 (g)		3,000		3,003,780
New Jersey EDA, Refunding RB, First Mortgage, Winchester, Series A, 5.80%, 11/01/31		1,500		1,534,965
New Jersey EDA, Special Assessment Bonds, Refunding, Kapkowski Road Landfill Project, 6.50%, 4/01/28		7,500		8,319,075
New Jersey Educational Facilities Authority, Refunding RB, University of Medicine & Dentistry, Series B:
7.13%, 12/01/23		630		778,037
7.50%, 12/01/32		800		976,448
New Jersey Health Care Facilities Financing Authority, Refunding RB, Barnabas Health, Series A:
4.63%, 7/01/23		510		516,145
5.63%, 7/01/37		1,700		1,791,358
New Jersey State Housing & Mortgage Finance Agency, RB, Series AA, 6.50%, 10/01/38		615		664,483
New Jersey Transportation Trust Fund Authority, RB, Transportation System, Series B, 5.25%, 6/15/36		1,900		2,128,152
Union County Utilities Authority, Refunding RB, County Deficiency Agreement, Series A:
4.00%, 6/15/32		250		262,510
5.00%, 6/15/41		95		106,219
				23,893,618


See Notes to Financial Statements.
18	SEMI-ANNUAL REPORT	FEBRUARY 29, 2012




Schedule of Investments (continued)	BlackRock Municipal Bond Trust (BBK)
Schedule of Investments (continued)	(Percentages shown are based on Net Assets)


Municipal Bonds		Par (000)		Value
New York — 5.8%
Albany Industrial Development Agency, RB, New Covenant Charter School Project, Series A, 7.00%, 5/01/35 (c)(d)	$	455	$	104,659
Hudson New York Yards Infrastructure Corp., RB, Series A:
5.00%, 2/15/47		250		257,255
(FGIC), 5.00%, 2/15/47		1,000		1,029,020
(NPFGC), 4.50%, 2/15/47		750		738,293
New York City Industrial Development Agency, RB, American Airlines Inc., JFK International Airport, AMT, 7.75%, 8/01/31 (c)(d)(g)		3,165		2,990,925
New York Convention Center Development Corp., RB (AMBAC), 4.75%, 11/15/45		1,000		1,007,710
New York Liberty Development Corp., Refunding RB, Second Priority, Bank of America Tower at One Bryant Park Project, 6.38%, 7/15/49		800		868,136
New York State Dormitory Authority, RB, Rochester Institute of Technology, Series A, 6.00%, 7/01/33		1,000		1,169,450
Westchester County Healthcare Corp. New York, RB, Senior Lien, Series A, Remarketing, 5.00%, 11/01/30		1,500		1,581,075
				9,746,523
North Carolina — 5.4%
City of Charlotte North Carolina, Refunding RB, Series A, 5.50%, 7/01/34		225		256,592
Gaston County Industrial Facilities & Pollution Control Financing Authority North Carolina, RB, Exempt Facilities, National Gypsum Co. Project, AMT, 5.75%, 8/01/35		2,945		2,413,486
North Carolina Capital Facilities Finance Agency, RB, Duke Energy Carolinas, Series B, 4.38%, 10/01/31		1,000		1,050,750
North Carolina Medical Care Commission, RB, Novant Health Obligation, Series A, 4.75%, 11/01/43		4,450		4,519,287
North Carolina Medical Care Commission, Refunding RB, University Health System, Series D, 6.25%, 12/01/33		800		926,600
				9,166,715
Oklahoma — 0.5%
Tulsa Airports Improvement Trust, RB, Series A, Mandatory Put Bonds, AMT, 7.75%, 6/01/35 (c)(d)(g)		1,025		793,852
Oregon — 1.7%
City of Portland Oregon, Multifamily Housing Revenue Bond Pass-Through Certificates, RB, Pacific Tower Apartments, Series 6, AMT, 6.05%, 11/01/34		505		505,146
Oregon Health & Science University, RB, Series A, 5.75%, 7/01/39		750		852,630
Oregon State Facilities Authority, Refunding RB, Limited College Project, Series A:
5.00%, 10/01/34		850		916,368
5.25%, 10/01/40		500		541,635
				2,815,779
Pennsylvania — 4.0%
County of Allegheny Pennsylvania IDA, Refunding RB, U.S. Steel Corp. Project, 6.55%, 12/01/27		1,695		1,800,192
Delaware River Port Authority, RB, Series D (AGM), 5.00%, 1/01/40		2,600		2,798,718
Pennsylvania Economic Development Financing Authority, RB, Aqua Pennsylvania Inc. Project, Series B, 4.50%, 12/01/42		2,000		2,094,220
				6,693,130


Municipal Bonds	Par (000)		Value
Puerto Rico — 1.4%
Puerto Rico Sales Tax Financing Corp., RB, CAB, Series A, 5.70%, 8/01/35 (a)	$	1,000	$	278,690
Puerto Rico Sales Tax Financing Corp., RB, First Sub-Series A, 5.75%, 8/01/37		1,000		1,117,510
Puerto Rico Sales Tax Financing Corp., Refunding RB, CAB, Series A (NPFGC), 5.73%, 8/01/41 (a)		5,000		1,001,600
				2,397,800
Rhode Island — 1.3%
Rhode Island Health & Educational Building Corp., RB, Hospital Financing, LifeSpan Obligation, Series A (AGC), 7.00%, 5/15/39		1,000		1,190,110
State of Rhode Island, COP, Series C, School for the Deaf (AGC), 5.38%, 4/01/28		900		1,014,129
				2,204,239
South Dakota — 0.9%
State of South Dakota Board of Regents Housing & Auxiliary Facility System Revenue, RB, 4.25%, 4/01/33		1,535		1,605,410
Tennessee — 0.2%
Memphis-Shelby County Sports Authority Inc., Refunding RB, Memphis Arena Project, Series A, 5.38%, 11/01/28		275		305,896
Texas — 13.4%
Harris County Health Facilities Development Corp., Refunding RB, Memorial Hermann Healthcare System, Series B:
7.13%, 12/01/31		500		602,825
7.25%, 12/01/35		1,750		2,090,498
Harris County Metropolitan Transit Authority Sales and Use Tax, RB, Series A, 5.00%, 11/01/36		940		1,058,919
Harris County-Houston Sports Authority, Refunding RB, CAB, Senior Lien, Series G (NPFGC), 6.18%, 11/15/41 (a)		11,690		1,717,612
Matagorda County Navigation District No. 1 Texas, Refunding RB, Central Power & Light Co. Project, Series A, 6.30%, 11/01/29		1,500		1,722,270
Texas Private Activity Bond Surface Transportation Corp., RB, Senior Lien, LBJ Infrastructure Group LLC, LBJ Freeway Managed Lanes Project, 7.00%, 6/30/40		2,000		2,274,160
Texas State Turnpike Authority, RB (AMBAC):
CAB, 6.08%, 8/15/35 (a)		50,000		12,308,500
First Tier, Series A, 5.00%, 8/15/42		750		750,375
				22,525,159
Vermont — 1.0%
Vermont Educational & Health Buildings Financing Agency, RB, Hospital, Fletcher Allen Health, Series A, 4.75%, 12/01/36		1,600		1,606,640
Virginia — 0.1%
Roanoke Economic Development Authority, RB, Carilion Clinic Obligated Group, 4.00%, 7/01/29		160		160,938
Washington — 1.9%
City of Lynnwood, GO (AGO), 4.00%, 12/01/37		1,600		1,597,360
Washington Health Care Facilities Authority, RB, MultiCare Health System, Series B (AGC), 6.00%, 8/15/39		1,400		1,588,132
				3,185,492
West Virginia — 0.7%
West Virginia State University, RB, West Virginia University Projects, Series B, 5.00%, 10/01/36		1,100		1,242,956


See Notes to Financial Statements.
	SEMI-ANNUAL REPORT	FEBRUARY 29, 2012	19



Schedule of Investments (concluded)	BlackRock Municipal Bond Trust (BBK)
	(Percentages shown are based on Net Assets)


Municipal Bonds	Par (000)		Value
Wisconsin — 0.7%
Wisconsin State Health & Educational Facilities Authority, RB, Aurora Health Care, Series A, 4.00%, 7/15/28	$	1,215	$	1,202,000
Wyoming — 0.8%
County of Sweetwater Wyoming, Refunding RB, Idaho Power Co. Project, 5.25%, 7/15/26		1,200		1,372,740
Total Municipal Bonds — 136.6%				230,052,557


Municipal Bonds Transferred to Tender Option Bond Trusts (h)
Colorado — 2.3%
Colorado Health Facilities Authority, RB, Catholic Health, Series C-7 (AGM), 5.00%, 9/01/36		3,750		3,940,537
Massachusetts — 1.0%
Massachusetts Water Resources Authority, Refunding RB, General, Series A, 5.00%, 8/01/41		1,450		1,592,724
New York — 7.3%
Hudson Yards Infrastructure Corp., RB, 5.75%, 2/15/47		2,500		2,824,461
New York City Municipal Water Finance Authority, RB: Fiscal 2009, Series A, 5.75%, 6/15/40		450		522,323
Series FF-2, 5.50%, 6/15/40		405		467,031
New York City Municipal Water Finance Authority, Refunding RB, Series A, 4.75%, 6/15/30		3,000		3,262,770
New York Liberty Development Corp., RB, 5.25%, 12/15/43		2,505		2,810,485
New York State Dormitory Authority, RB, New York University, Series A, 5.00%, 7/01/38		2,199		2,368,575
				12,255,645
Ohio — 2.1%
County of Montgomery Ohio, RB, Catholic Health, Series C-1 (AGM), 5.00%, 10/01/41		1,260		1,355,269
Ohio Higher Educational Facility Commission, Refunding RB, Hospital, Cleveland Clinic Health, Series A, 5.25%, 1/01/33		2,000		2,154,820
				3,510,089
Total Municipal Bonds Transferred to Tender Option Bond Trusts — 12.7%				21,298,995
Total Long-Term Investments (Cost — $234,380,899) — 149.3%				251,351,552



Short-Term Securities	Shares
FFI Institutional Tax-Exempt Fund, 0.01% (i)(j)		4,946,999		4,946,999
Total Short-Term Securities (Cost — $4,946,999) — 2.9%				4,946,999
Total Investments (Cost — $239,327,898) — 152.2%				256,298,551
Other Assets Less Liabilities — 1.4%				2,278,896
Liability for TOB Trust Certificates, Including Interest Expense and Fees Payable — (6.1)%				(10,322,024	)
VMTP Shares, at Liquidation Value — (47.5)%				(79,900,000	)
Net Assets Applicable to Common Shares — 100.0%			$	168,355,423


(a)	Represents a zero-coupon bond. Rate shown reflects the current yield as of report date.

(b)	Represents a step-up bond that pays an initial coupon rate for the first period and then a higher coupon rate for the following periods. Rate shown is as of report date.

(c)	Issuer filed for bankruptcy and/or is in default of interest payments.

(d)	Non-income producing security.

(e)	Security represents a beneficial interest in a trust. The collateral deposited into the trust is federally tax-exempt revenue bonds issued by various state or local governments, or their respective agencies or authorities. The security is subject to remarketing prior to its stated maturity.

(f)	Security exempt from registration pursuant to Rule 144A under the Securities Act of 1933. These securities may be resold in transactions exempt from registration to qualified institutional investors.

(g)	Variable rate security. Rate shown is as of report date and maturity shown is the date the principal owed can be recovered through demand.

(h)	Securities represent bonds transferred to a TOB in exchange for which the Trust acquired residual interest certificates. These securities serve as collateral in a financing transaction. See Note 1 of the Notes to Financial Statements for details of municipal bonds transferred to TOBs.

(i)	Investments in companies considered to be an affiliate of the Trust during the period, for purposes of Section 2(a)(3) of the Investment Company Act of 1940, as amended, were as follows:


Affiliate	Shares Held at August 31, 2011	Net Activity	Shares Held at February 29, 2012	Income
FFI Institutional
Tax-Exempt Fund	2,247,948	2,699,051	4,946,999	$319


(j)	Represents the current yield as of report date.

•	Fair Value Measurements — Various inputs are used in determining the fair value of investments. These inputs are categorized into a disclosure hierarchy consisting of three broad levels for financial statement purposes as follows:

	•	Level 1 — unadjusted price quotations in active markets/exchanges for identical assets and liabilities

	•	Level 2 — other observable inputs (including, but not limited to: quoted prices for similar assets or liabilities in markets that are active, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the assets or liabilities (such as interest rates, yield curves, volatilities, prepayment speeds, loss severities, credit risks and default rates) or other market-corroborated inputs)

	•	Level 3 — unobservable inputs based on the best information available in the circumstances, to the extent observable inputs are not available (including the Trust’s own assumptions used in determining the fair value of investments)

Changes in valuation techniques may result in transfers in or out of an assigned level within the disclosure hierarchy. The categorization of a value determined for investments is based on the pricing transparency of the investment and does not necessarily correspond to the Trust’s perceived risk of investing in those securities. For information about the Trust’s policy regarding valuation of investments and other significant accounting policies, please refer to Note 1 of the Notes to Financial Statements.

The following table summarizes the inputs used as of February 29, 2012 in determining the fair valuation of the Trust’s investments:


Valuation Inputs	Level 1		Level 2		Level 3		Total
Assets:
Investments:
Long-Term Investments¹		—	$	251,351,552		—	$	251,351,552
Short-Term Securities	$	4,946,999		—		—		4,946,999
Total	$	4,946,999	$	251,351,552		—	$	256,298,551


	¹	See above Schedule of Investments for values in each state or political subdivision.


See Notes to Financial Statements.

20	SEMI-ANNUAL REPORT	FEBRUARY 29, 2012



Schedule of Investments February 29, 2012 (Unaudited)	BlackRock Municipal Income Investment Quality Trust (BAF)
	(Percentages shown are based on Net Assets)


Municipal Bonds	Par (000)		Value
Alabama — 1.9%
Birmingham Special Care Facilities Financing Authority, RB, Children’s Hospital (AGC):
6.13%, 6/01/34	$	1,000	$	1,150,950
6.00%, 6/01/39		1,000		1,142,790
Selma IDB, RB, International Paper Co. Project, Series A, 5.38%, 12/01/35		370		387,564
				2,681,304
California — 11.9%
California Educational Facilities Authority, RB, University of Southern California, Series A, 5.25%, 10/01/38		2,155		2,458,769
California Health Facilities Financing Authority, RB:
Scripps, Series A, 5.00%, 11/15/40		175		190,132
Sutter Health, Series B, 6.00%, 8/15/42		1,120		1,294,216
County of Sacramento California, RB, Senior Series A (AGC), 5.50%, 7/01/41		1,400		1,518,104
Los Angeles Community College District California, GO:
Election of 2001, Series A (NPFGC), 5.00%, 8/01/32		1,000		1,099,900
Election of 2008, Series C, 5.25%, 8/01/39		500		573,150
Los Angeles Department of Water & Power, RB, Power System, Sub-Series A-1, 5.25%, 7/01/38		1,175		1,339,770
Los Angeles Municipal Improvement Corp., Refunding RB, Real Property, Series B (AGC), 5.50%, 4/01/39		3,210		3,537,837
Redondo Beach Unified School District, GO, Election of 2008, Series E, 5.50%, 8/01/34		1,000		1,162,810
San Bernardino Community College District, GO, Election of 2002, Series A, 6.25%, 8/01/33		925		1,100,584
San Diego Public Facilities Financing Authority, Refunding RB, Series B (AGC), 5.38%, 8/01/34		1,125		1,299,960
San Jacinto Unified School District, GO, Election of 2006 (AGM), 5.25%, 8/01/32		1,000		1,085,210
				16,660,442
Colorado — 1.2%
Colorado Health Facilities Authority, RB, Hospital, NCMC Inc. Project, Series B (AGM), 6.00%, 5/15/26		1,425		1,670,627
Florida — 5.4%
City of Jacksonville Florida, RB, Series A, 5.25%, 10/01/31		4,525		5,188,998
Orange County Health Facilities Authority, RB, The Nemours Foundation Project, Series A, 5.00%, 1/01/29		1,070		1,168,172
Village Center Community Development District, RB, Series A (NPFGC), 5.00%, 11/01/32		1,250		1,238,789
				7,595,959
Georgia — 2.2%
City of Atlanta Georgia, Refunding RB, General, Series C, 6.00%, 1/01/30		2,500		3,045,850
Illinois — 15.4%
Chicago Board of Education Illinois, GO, Series A:
5.50%, 12/01/39		1,500		1,698,300
5.00%, 12/01/41		1,000		1,078,380
Chicago Transit Authority, RB Federal Transit Administration Section 5309, Series A (AGC), 6.00%, 6/01/26		1,300		1,526,304
Chicago Transit Authority, RB, Sales Tax Receipts Revenue:
5.25%, 12/01/36		415		461,853
5.25%, 12/01/40		1,325		1,471,187
City of Chicago Illinois, RB:
General Third Lien, Series C, 5.25%, 1/01/30		1,000		1,110,330
Sales Tax Revenue, Series A, 5.25%, 1/01/38		515		577,145
Third Lien, O’Hare International Airport, Series A, 5.75%, 1/01/39		825		946,778

Municipal Bonds	Par (000)		Value
Illinois (concluded)
City of Chicago Illinois, Refunding RB, General, Third Lien, (AGM), Series C, 6.50%, 1/01/41	$	3,740	$	4,501,240
Illinois Finance Authority, RB, Carle Foundation, Series A, 6.00%, 8/15/41		1,885		2,068,882
Illinois Municipal Electric Agency, RB, Series A (NPFGC):
5.25%, 2/01/28		1,560		1,714,222
5.25%, 2/01/35		1,000		1,069,600
Railsplitter Tobacco Settlement Authority, RB:
5.50%, 6/01/23		915		1,053,879
6.00%, 6/01/28		260		290,909
State of Illinois, RB, Build Illinois, Series B, 5.25%, 6/15/28		1,750		1,971,952
				21,540,961
Indiana — 5.6%
Indiana Finance Authority Wastewater Utility, RB, First
Lien, CWA Authority, Series A:
5.25%, 10/01/31		1,000		1,144,110
5.25%, 10/01/38		2,000		2,226,060
Indianapolis Local Public Improvement Bond Bank, RB, Series K (AGM), 5.00%, 6/01/25		1,570		1,786,942
Indianapolis Local Public Improvement Bond Bank, Refunding RB, Waterworks Project, Series A (AGC), 5.50%, 1/01/38		2,415		2,697,048
				7,854,160
Iowa — 0.2%
Iowa Finance Authority, Refunding RB, Iowa Health System (AGC), 5.25%, 2/15/29		305		335,149
Louisiana — 0.5%
New Orleans Aviation Board Louisiana, Refunding RB, GARB, Restructuring, (AGC):
Series A-1, 6.00%, 1/01/23		375		447,656
Series A-2, 6.00%, 1/01/23		150		179,063
				626,719
Michigan — 14.7%
City of Detroit Michigan, RB:
Second Lien, Series B (NPFGC), 5.50%, 7/01/29		1,690		1,903,227
Senior Lien, Series B (AGM), 7.50%, 7/01/33		580		729,402
Senior Lien, Series B (BHAC), 5.50%, 7/01/35		4,750		5,195,218
System, Second Lien, Series A (BHAC), 5.50%, 7/01/36		2,330		2,570,456
City of Detroit Michigan, RB, Second Lien, Series B (AGM), 6.25%, 7/01/36		1,700		1,949,220
City of Detroit Michigan, Refunding RB, Senior Lien, Series C-1 (AGM), 7.00%, 7/01/27		1,800		2,220,264
Lansing Board of Water & Light Utilities, RB, Series A, 5.00%, 7/01/37		2,765		3,071,887
Michigan State Building Authority, RB, Facilities Program, Series H (AGM), 5.00%, 10/15/26		365		410,771
Michigan State Building Authority, Refunding RB, Facilities Program, Series I (AGC):
5.25%, 10/15/24		565		649,462
5.25%, 10/15/25		300		343,527
Royal Oak Hospital Finance Authority Michigan, Refunding RB, William Beaumont Hospital, 8.25%, 9/01/39		1,205		1,517,842
				20,561,276
Minnesota — 3.1%
City of Minneapolis Minnesota, Refunding RB, Fairview Health Services, Series B (AGC), 6.50%, 11/15/38		3,680		4,327,790
Missouri — 1.9%
Missouri Municipal Electric Utility Commission Power, RB, Prairie State Project, Series A, 5.00%, 1/01/32 (a)		2,500		2,686,775


See Notes to Financial Statements.

	SEMI-ANNUAL REPORT	FEBRUARY 29, 2012	21



Schedule of Investments (continued)	BlackRock Municipal Income Investment Quality Trust (BAF)
Schedule of Investments (continued)	(Percentages shown are based on Net Assets)


Municipal Bonds	Par (000)		Value
Nevada — 1.6%
Clark County Water Reclamation District, GO, Series A, 5.25%, 7/01/34	$	2,000	$	2,232,940
New Jersey — 4.6%
New Jersey Health Care Facilities Financing Authority, RB, Virtua Health (AGC), 5.50%, 7/01/38		1,300		1,418,573
New Jersey State Housing & Mortgage Finance Agency, RB, S/F Housing, Series CC, 5.25%, 10/01/29		1,575		1,691,393
New Jersey Transportation Trust Fund Authority, RB, Transportation System:
Series A (AGC), 5.50%, 12/15/38		2,000		2,219,480
Series B, 5.25%, 6/15/36		1,000		1,120,080
				6,449,526
New York — 5.5%
New York City Transitional Finance Authority, RB:
Series S-3, 5.25%, 1/15/39		900		988,578
Sub-Future Tax Secured, Series C, 5.00%, 11/01/39		1,175		1,305,801
New York City Transitional Finance Authority, RB, Fiscal 2009, Series S-4 (AGC), 5.50%, 1/15/29		2,465		2,873,623
New York State Dormitory Authority, RB, General Purpose, Series C, 5.00%, 3/15/41		2,220		2,468,951
				7,636,953
Pennsylvania — 0.6%
Philadelphia Hospitals & Higher Education Facilities Authority, RB, Childrens Hospital Philadelphia, Series D, 5.00%, 7/01/32		710		785,246
Puerto Rico — 1.1%
Puerto Rico Sales Tax Financing Corp., RB, First Sub-Series A, 6.38%, 8/01/39		1,350		1,582,470
Texas — 22.8%
Austin Community College District, RB, Educational Facilities Project, Round Rock Campus, 5.25%, 8/01/33		2,000		2,188,860
City of Austin Texas, Refunding RB, Series A (AGM):
5.00%, 11/15/28		705		802,502
5.00%, 11/15/29		895		1,010,052
City of Houston Texas, Refunding RB, Combined, First Lien, Series A (AGC):
6.00%, 11/15/35		2,600		3,134,092
6.00%, 11/15/36		2,215		2,658,797
5.38%, 11/15/38		1,000		1,140,400
Clifton Higher Education Finance Corp., Refunding RB, Baylor University, 5.25%, 3/01/32		1,270		1,453,070
Frisco ISD Texas, GO, School Building (AGC), 5.50%, 8/15/41		3,365		3,997,856
Harris County Cultural Education Facilities Finance Corp., RB, Texas Children’s Hospital Project, 5.25%, 10/01/29		875		997,518
Harris County Health Facilities Development Corp., Refunding RB, Memorial Hermann Healthcare System, Series B, 7.13%, 12/01/31		500		602,825
Lamar Texas Consolidated Independent School District, GO, Refunding RB, School House, Series A, 5.00%, 2/15/45 (a)		890		1,004,641
Lubbock Cooper ISD Texas, GO, School Building (AGC), 5.75%, 2/15/42		500		562,715
North Texas Tollway Authority, RB, Special Projects System, Series A, 5.50%, 9/01/41		1,000		1,150,930
North Texas Tollway Authority, Refunding RB:
System, First Tier (AGM), 6.00%, 1/01/43		1,000		1,167,070
System, First Tier, Series A (AGC), 5.75%, 1/01/40		1,500		1,654,275
System, First Tier, Series K-1 (AGC), 5.75%, 1/01/38		1,500		1,678,455


Municipal Bonds	Par (000)		Value
Texas (concluded)
Tarrant County Cultural Education Facilities Finance Corp., Refunding RB, Christus Health, Series A (AGC), 6.50%, 7/01/37	$	1,000	$	1,150,810
University of Texas System, Refunding RB, Financing System, Series B, 5.00%, 8/15/43 (a)		1,805		2,071,129
Waco Educational Finance Corporation, RB, Baylor University, 5.00%, 3/01/43		3,000		3,352,920
				31,778,917
Utah — 0.8%
City of Riverton Utah, RB, IHC Health Services Inc., 5.00%, 8/15/41		1,000		1,073,950
Virginia — 0.9%
Virginia Public School Authority, RB, School Financing, 6.50%, 12/01/35		1,000		1,176,400
Washington — 5.5%
City of Seattle Washington, Refunding RB, Series A, 5.25%, 2/01/36		1,025		1,172,395
Port of Seattle, Refunding RB, Intermediate, Series A, 5.00%, 8/01/32 (a)		3,000		3,412,560
State of Washington, GO, Various Purpose, Series B, 5.25%, 2/01/36		795		914,616
University of Washington, Refunding, RB, Series A, 5.00%, 7/01/41 (a)		1,850		2,102,673
				7,602,244
Total Municipal Bonds — 107.4%				149,905,658



Municipal Bonds Transferred to Tender Option Bond Trusts (b)
Alabama — 1.1%
Mobile Board of Water & Sewer Commissioners, RB (NPFGC), 5.00%, 1/01/31	1,500	1,583,970
California — 10.7%
San Diego Community College District California, GO, Election of 2002 (AGM), 5.00%, 5/01/30	2,500	2,756,925
San Marcos Unified School District, GO, Election of 2010, Series A, 5.25%, 8/01/31	10,680	12,196,453
		14,953,378
District of Columbia — 0.7%
District of Columbia Water & Sewer Authority, RB, Series A, 6.00%, 10/01/35	760	942,608
Florida — 10.1%
City of Jacksonville Florida, RB, Better Jacksonville (NPFGC), 5.00%, 10/01/27	3,930	4,150,237
County of Pinellas Florida, RB (AGM), 5.00%, 10/01/32	9,500	9,993,568
		14,143,805
Illinois — 4.7%
Chicago Transit Authority, Refunding RB, Federal Transit Administration Section 5309 (AGM), 5.00%, 6/01/28	2,999	3,247,458
Illinois State Toll Highway Authority, RB, Series B, 5.50%, 1/01/33	2,999	3,285,500
		6,532,958
Kentucky — 0.7%
Kentucky State Property & Building Commission, Refunding RB, Project No. 93 (AGC), 5.25%, 2/01/27	898	1,025,816


See Notes to Financial Statements.

22	SEMI-ANNUAL REPORT	FEBRUARY 29, 2012



Schedule of Investments (continued)	BlackRock Municipal Income Investment Quality Trust (BAF)
Schedule of Investments (continued)	(Percentages shown are based on Net Assets)


Municipal Bonds Transferred to Tender Option Bond Trusts (b)	Par (000)		Value
Massachusetts — 1.6%
Massachusetts School Building Authority, RB, 5.00%, 10/15/41	$	2,000	$	2,245,080
Nevada — 5.0%
Clark County Water Reclamation District, GO, Limited Tax, 6.00%, 7/01/38		2,000		2,325,120
Las Vegas Valley Water District, GO, Refunding, Series C, 5.00%, 6/01/28		4,100		4,701,101
				7,026,221
New Jersey — 0.8%
New Jersey EDA, RB, School Facilities Construction, Series Z (AGC), 6.00%, 12/15/34		1,000		1,150,600
New York — 8.7%
Hudson Yards Infrastructure Corp., RB, Series A, 5.75%, 2/15/47		1,000		1,129,785
New York City Municipal Water Finance Authority, RB, Second General Resolution, Fiscal 2012, Series BB, 5.25%, 6/15/44		4,993		5,650,012
New York Liberty Development Corp., 5.25%, 12/15/43		2,955		3,315,362
New York State Liberty Development Corp., Refunding RB, 4 World Trade Center Project, 5.75%, 11/15/51		1,740		1,976,936
				12,072,095
Puerto Rico — 1.0%
Puerto Rico Sales Tax Financing Corp., RB, Series C, 5.25%, 8/01/40		1,180		1,310,461
Texas — 1.9%
North Texas Tollway Authority, RB, Special Projects, System, Series A, 5.50%, 9/01/41		2,310		2,658,648
Total Municipal Bonds Transferred to Tender Option Bond Trusts — 47.0%				65,645,640
Total Long-Term Investments (Cost — $197,730,152) — 154.4%				215,551,298


Short-Term Securities	Par (000)		Value
Illinois — 2.8%
Illinois Finance Authority, RB, VRDN, University of Chicago Medical Center, Series B, 0.12%, 3/01/12 (c)	$	3,900	$	3,900,000
Texas — 0.8%
Harris County Health Facilities Development Corp., RB, VRDN, Baylor College Medicine, Series B, 0.10%, 3/01/12 (c)		1,100		1,100,000

		Shares
Money Market Funds — 2.3%
FFI Institutional Tax-Exempt Fund, 0.01% (d)(e)		3,259,592		3,259,592
Total Short-Term Securities (Cost — $8,259,592) — 5.9%				8,259,592
Total Investments (Cost — $205,989,744) — 160.3%				223,810,890
Liabilities in Excess of Other Assets — (6.8)%				(9,444,749	)
Liability for TOB Trust Certificates, Including Interest Expense and Fees Payable — (23.3)%				(32,587,769	)
VMTP Shares, at Liquidation Value — (30.2)%				(42,200,000	)
Net Assets Applicable to Common Shares — 100.0%			$	139,578,372


See Notes to Financial Statements.

	SEMI-ANNUAL REPORT	FEBRUARY 29, 2012	23



Schedule of Investments (concluded)	BlackRock Municipal Income Investment Quality Trust (BAF)


(a)	When-issued security. Unsettled when-issued transactions were as follows:



Counterparty	Value		Unrealized Appreciation
Morgan Keegan & Co.	$	1,004,641	$	3,791
National Financial	$	2,686,775		—
Pershing LLC	$	1,134,240	$	3,280
JPMorgan Securities	$	2,268,480	$	6,560
Morgan Stanley Co.	$	2,071,129	$	18,375
Barclays Capital Inc.	$	2,102,673	$	14,208


(b)	Securities represent bonds transferred to a TOB in exchange for which the Trust acquired residual interest certificates. These securities serve as collateral in a financing transaction. See Note 1 of the Notes to Financial Statements for details of municipal bonds transferred to TOBs.

(c)	Variable rate security. Rate shown is as of report date and maturity shown is the date the principal owed can be recovered through demand.

(d)	Investments in companies considered to be an affiliate of the Trust during the period, for purposes of Section 2(a)(3) of the Investment Company Act of 1940, as amended, were as follows:



Affiliate	Shares Held at August 31, 2011		Net Activity			Shares Held at February 29, 2012		Income
FFI Institutional Tax-Exempt Fund		9,230,241		(5,970,649	)		3,259,592	$	153


(e)	Represents the current yield as of report date.

•	Financial futures contracts sold as of February 29, 2012 were as follows:

Contracts

Issue

Exchange

Expiration

Notional
Value

Unrealized
Depreciation

10-Year US

Chicago

March

6,169,484

(36,074

)

Treasury Note

Board of Trade

2012


•	Fair Value Measurements — Various inputs are used in determining the fair value of investments and derivative financial instruments. These inputs are categorized into a disclosure hierarchy consisting of three broad levels for financial statement purposes as follows:

	•	Level 1 — unadjusted price quotations in active markets/exchanges for identical assets and liabilities

	•	Level 2 — other observable inputs (including, but not limited to: quoted prices for similar assets or liabilities in markets that are active, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the assets or liabilities (such as interest rates, yield curves, volatilities, prepayment speeds, loss severities, credit risks and default rates) or other market-corroborated inputs)

	•	Level 3 — unobservable inputs based on the best information available in the circumstances, to the extent observable inputs are not available (including the Trust’s own assumptions used in determining the fair value of investments and derivative financial instruments)

	Changes in valuation techniques may result in transfers in or out of an assigned level within the disclosure hierarchy. The categorization of a value determined for investments and derivative financial instruments is based on the pricing transparency of the investment and derivative financial instrument and does not necessarily correspond to the Trust’s perceived risk of investing in those securities. For information about the Trust’s policy regarding valuation of investments and derivative financial instruments and other significant accounting policies, please refer to Note 1 of the Notes to Financial Statements.

	The following tables summarize the inputs used as of February 29, 2012 in determining the fair valuation of the Trust’s investments and derivative financial instruments:



Valuation Inputs	Level 1		Level 2		Level 3		Total
Assets:
Investments:
Long-Term Investments¹		—	$	215,551,298		—	$	215,551,298
Short-Term Securities	$	3,259,592		5,000,000		—		8,259,592
Total	$	3,259,592	$	220,551,298		—	$	223,810,890


	¹	See above Schedule of Investments for values in each state or political subdivision.



Valuation Inputs	Level 1			Level 2		Level 3		Total
Derivative Financial
Instruments²
Assets:
Interest rate contracts	$	(36,074	)		—		—	$	(36,074	)


	²	Derivative financial instruments are financial futures contracts, which are valued at the unrealized appreciation/depreciation on the instrument.


See Notes to Financial Statements.

24	SEMI-ANNUAL REPORT	FEBRUARY 29, 2012



Schedule of Investments February 29, 2012 (Unaudited)	BlackRock Municipal Income Quality Trust (BYM)
	(Percentages shown are based on Net Assets)


Municipal Bonds	Par (000)		Value
Alabama — 3.7%
Alabama State Docks Department, Refunding RB, 6.00%, 10/01/40	$	3,800	$	4,213,592
Birmingham Airport Authority, RB (AGM), 5.50%, 7/01/40		5,800		6,424,428
Birmingham Special Care Facilities Financing Authority, RB, Children’s Hospital (AGC), 6.00%, 6/01/39		1,495		1,708,471
County of Jefferson Alabama, RB, Series A, 4.75%, 1/01/25		2,800		2,548,028
				14,894,519
Alaska — 0.3%
Alaska Industrial Development & Export Authority, RB, Providence Health Services, Series A, 5.50%, 10/01/41		1,070		1,194,933
Arizona — 0.5%
State of Arizona, COP, Department of Administration, Series A (AGM):
5.00%, 10/01/27		1,500		1,684,575
5.25%, 10/01/28		250		283,560
				1,968,135
California — 22.8%
California Health Facilities Financing Authority, RB, St. Joseph Health System, Series A, 5.75%, 7/01/39		625		691,419
California Infrastructure & Economic Development Bank, RB, Bay Area Toll Bridges, First Lien, Series A (AMBAC), 5.00%, 7/01/36 (a)		10,100		13,511,174
Coast Community College District California, GO, Refunding, CAB, Election of 2002, Series C (AGM):
5.00%, 8/01/13 (b)		7,450		7,090,463
5.41%, 8/01/36 (c)		4,200		1,105,734
Golden State Tobacco Securitization Corp. California, RB, Series 2003-A-1 (a):
6.75%, 6/01/39		14,500		15,653,765
6.63%, 6/01/40		6,500		7,007,065
Metropolitan Water District of Southern California, RB, Series B-1 (NPFGC), 5.00%, 10/01/33		16,745		17,997,024
Monterey Peninsula Community College District, GO, CAB, Series C (AGM) (c):
5.15%, 8/01/31		13,575		5,091,575
5.16%, 8/01/32		14,150		4,881,325
Orange County Sanitation District, COP, Series B (AGM), 5.00%, 2/01/31		2,500		2,737,950
San Diego Unified School District California, GO, CAB, Election of 2008, Series C, 6.84%, 7/01/38 (c)		2,000		491,500
San Joaquin Hills Transportation Corridor Agency California, Refunding RB, CAB, Series A (NPFGC), 5.51%, 1/15/31 (c)		53,000		14,045,000
San Jose Unified School District Santa Clara County California, GO, Election of 2002, Series B (NPFGC), 5.00%, 8/01/29		2,350		2,502,515
				92,806,509
Colorado — 0.3%
Regional Transportation District, COP, Series A, 5.38%, 6/01/31		960		1,074,883
District of Columbia — 2.3%
District of Columbia Tobacco Settlement Financing Corp., Refunding RB, Asset-Backed, 6.75%, 5/15/40		9,500		9,581,035
Florida — 15.8%
Broward County School Board Florida, COP, Series A (AGM), 5.25%, 7/01/33		1,600		1,722,976
County of Broward Florida, RB, Series A, 5.25%, 10/01/34		6,750		7,523,550
County of Duval Florida, COP, Master Lease Program (AGM), 5.00%, 7/01/33		3,800		4,020,172

Municipal Bonds	Par (000)		Value
Florida (concluded)
County of Miami-Dade Florida, RB:
CAB, Sub-Series A (NPFGC), 5.25%, 10/01/38 (c)	$	25,520	$	5,313,009
Miami International Airport, Series A, 5.50%, 10/01/41		5,000		5,594,400
Series A, 5.50%, 10/01/36		5,000		5,538,250
Series B (AGC), 5.25%, 5/01/31		1,135		1,238,421
Water & Sewer System (AGM), 5.00%, 10/01/39		10,100		10,949,915
County of Miami-Dade Florida, Refunding RB (AGM), 5.00%, 7/01/35		1,300		1,386,333
County of Miami-Dade Florida, School Board, COP, RB, Series B (AGC), 5.25%, 5/01/31		1,135		1,238,421
Florida Housing Finance Corp., RB, Homeowner Mortgage, Series 3, 5.45%, 7/01/33		3,800		4,023,288
Florida State Department of Environmental Protection, RB, Series B (NPFGC), 5.00%, 7/01/27		6,150		6,814,507
Orange County School Board, COP, Series A (AGC), 5.50%, 8/01/34		6,090		6,749,791
Sarasota County Public Hospital District, RB, Sarasota Memorial Hospital Project, Series A, 5.63%, 7/01/39		300		321,651
South Florida Water Management District, COP (AMBAC), 5.00%, 10/01/36		1,000		1,050,490
Tohopekaliga Water Authority, Refunding RB, Series A, 5.25%, 10/01/36		2,000		2,256,880
				64,503,633
Georgia — 2.8%
Burke County Development Authority, RB, Oglethorpe Power, Vogtle Project, Series C, 5.70%, 1/01/43		1,250		1,342,237
City of Atlanta Georgia, Refunding RB, General, Series C, 6.00%, 1/01/30		7,500		9,137,550
Gwinnett County Hospital Authority, Refunding RB, Gwinnett Hospital System Series D (AGM), 5.50%, 7/01/41		900		986,868
				11,466,655
Hawaii — 1.4%
Hawaii State Harbor, RB, Series A, 5.25%, 7/01/35		5,000		5,545,800
Illinois — 3.1%
Chicago Board of Education Illinois, GO, Series A, 5.50%, 12/01/39		2,590		2,932,398
Chicago Park District, GO, Harbor Facilities, Series C, 5.25%, 1/01/40		600		659,094
Chicago Transit Authority, RB, 5.25%, 12/01/36		650		723,385
City of Chicago Illinois, RB, Series A (AGC), 5.00%, 1/01/38		7,310		7,648,160
Railsplitter Tobacco Settlement Authority, RB, 6.00%, 6/01/28		710		794,405
				12,757,442
Indiana — 2.0%
Indiana Finance Authority Wastewater Utility, Refunding RB, First Lien, CWA Authority, Series A, 5.25%, 10/01/38		1,100		1,224,333
Indiana Municipal Power Agency, RB, Series B, 5.75%, 1/01/34		450		481,995
Indianapolis Local Public Improvement Bond Bank, Refunding RB, Waterworks Project, Series A (AGC), 5.50%, 1/01/38		5,750		6,421,543
				8,127,871
Iowa — 1.3%
Iowa Finance Authority, RB, Series A (AGC), 5.63%, 8/15/37		5,000		5,495,900
Kentucky — 0.4%
Kentucky State Property & Buildings Commission, Refunding RB, Project No. 93 (AGC), 5.25%, 2/01/29		1,500		1,692,525


See Notes to Financial Statements.

	SEMI-ANNUAL REPORT	FEBRUARY 29, 2012	25



Schedule of Investments (continued)	BlackRock Municipal Income Quality Trust (BYM)
	(Percentages shown are based on Net Assets)


Municipal Bonds	Par (000)		Value
Louisiana — 2.8%
Jefferson Parish Hospital Service District No. 1, Refunding RB, West Jefferson Medical Center, Series A, 6.00%, 1/01/39	$	1,550	$	1,721,492
Parish of Saint John the Baptist Louisiana, RB, Marathon Oil Corp., Series A, 5.13%, 6/01/37