BIE Blackrock Municipal Bond Investment Trust

000 B000000 08/31/2012
000 C000000 0001169028
000 D000000 N
000 E000000 NF
000 F000000 Y
000 G000000 N
000 H000000 N
000 I000000 6.1
000 J000000 A
001 A000000 BLACKROCK MUNICIPAL BOND INVESTMENT TRUST
001 B000000 811-21054
001 C000000 8004417762
002 A000000 100 BELLEVUE PARKWAY
002 B000000 WILMINGTON
002 C000000 DE
002 D010000 19809
003 000000 N
004 000000 N
005 000000 N
006 000000 N
007 A000000 N
007 B000000 0
007 C010100 1
008 A000001 BLACKROCK ADVISORS, LLC
008 B000001 A
008 C000001 801-47710
008 D010001 WILMINGTON
008 D020001 DE
008 D030001 19809
008 A000002 BLACKROCK FINANCIAL MANAGEMENT, INC.
008 B000002 S
008 C000002 801-48433
008 D010002 NEW YORK
008 D020002 NY
008 D030002 10055
012 A000001 COMPUTERSHARE TRUST COMPANY, N.A.
012 B000001 85-11340
012 C010001 CANTON
012 C020001 MA
012 C030001 02021
012 A000002 THE BANK OF NEW YORK MELLON (PREFERRED)
012 B000002 85-05006
012 C010002 NEW YORK
012 C020002 NY
012 C030002 10289
013 A000001 DELOITTE & TOUCHE LLP
013 B010001 BOSTON
013 B020001 MA
013 B030001 02116
014 A000001 BLACKROCK CAPITAL MARKETS, LLC
014 B000001 8-67827

014 A000002 BLACKROCK EXECUTION SERVICES
014 B000002 8-48719
014 A000003 BLACKROCK INVESTMENTS, LLC
014 B000003 8-48436
014 A000004 HARRIS WILLIAMS LLC
014 B000004 8-53380
014 A000005 PNC CAPITAL MARKETS, INC.
014 B000005 8-32493
014 A000006 PNC INVESTMENTS LLC
014 B000006 8-66195
015 A000001 STATE STREET BANK & TRUST COMPANY
015 B000001 C
015 C010001 BOSTON
015 C020001 MA
015 C030001 02110
015 A000002 THE BANK OF NEW YORK MELLON
015 B000002 S
015 C010002 NEW YORK
015 C020002 NY
015 C030002 10286
015 E010002 X
015 A000003 J.P. MORGAN CHASE BANK
015 B000003 S
015 C010003 NEW YORK
015 C020003 NY
015 C030003 10017
015 E010003 X
018 000000 Y
019 A000000 Y
019 B000000 289
019 C000000 BLKRKADVSR
020 A000001 BANK OF AMERICA CORP
020 B000001 56-0906609
020 C000001 1
020 A000002 JANNEY MONTGOMERY SCOTT LLC
020 B000002 23-0731260
020 C000002 0
021 000000 1
022 A000001 FFI INSTITUTIONAL TAX-EXEMPT FUND
022 B000001 22-2509978
022 C000001 23685
022 D000001 25716
022 A000002 PERSHING LLC
022 B000002 13-2741729
022 C000002 7631
022 D000002 5221
022 A000003 CITIGROUP GLOBAL MARKETS, INC.
022 B000003 11-2418191
022 C000003 4838
022 D000003 3474
022 A000004 J.P. MORGAN SECURITIES INC.

022 B000004 13-3299429
022 C000004 5815
022 D000004 1845
022 A000005 MORGAN STANLEY & CO. INCORPORATED
022 B000005 13-2655998
022 C000005 4899
022 D000005 2310
022 A000006 STIFEL, NICOLAUS & COMPANY, INCORPORATED
022 B000006 43-0538770
022 C000006 2338
022 D000006 2476
022 A000007 WELLS FARGO & CO
022 B000007 41-0449260
022 C000007 1736
022 D000007 1656
022 A000008 BARCLAYS CAPITAL INC.
022 B000008 13-3299429
022 C000008 2433
022 D000008 0
022 A000009 GOLDMAN SACHS & CO
022 B000009 13-5108880
022 C000009 2304
022 D000009 0
022 A000010 BANK OF AMERICA CORP
022 B000010 56-0906609
022 C000010 242
022 D000010 2035
023 C000000 58231
023 D000000 53242
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075 A000000 0
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076 000000 16.61
077 A000000 Y
077 B000000 Y
077 E000000 Y
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078 000000 N
080 A000000 FEDERAL INSURANCE COMPANY
080 B000000 NATIONAL UNION FIRE INS. CO. OF PITTSBURGH PA
080 C000000 69325
081 A000000 Y
081 B000000 94
082 A000000 N
082 B000000 0
083 A000000 N
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086 D010000 1
086 D020000 17850
086 E010000 0
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087 A010000 COMMON STOCK
087 A020000 09249K107
087 A030000 BIE
087 B010000 PREFERRED STOCK
088 A000000 N
088 B000000 N
088 C000000 N
088 D000000 Y
SIGNATURE NEAL J. ANDREWS
TITLE CFO