<PAGE> PAGE 1
000 A000000 05/31/97
000 C000000 0000106830
000 D000000 N
000 E000000 NF
000 F000000 Y
000 G000000 N
000 H000000 N
000 I000000 3.0.a
000 J000000 U
001 A000000 VANGUARD MONEY MARKET RESERVES, INC.
001 B000000 811-2554
001 C000000 6106691000
002 A000000 100 VANGUARD BOULEVARD
002 B000000 MALVERN
002 C000000 PA
002 D010000 19355
003 000000 N
004 000000 N
005 000000 N
006 000000 N
007 A000000 Y
007 B000000 2
007 C010100 1
007 C020100 PRIME PORTFOLIO
007 C030100 N
007 C010200 2
007 C020200 FEDERAL PORTFOLIO
007 C030200 N
007 C010300 3
007 C010400 4
007 C010500 5
007 C010600 6
007 C010700 7
007 C010800 8
007 C010900 9
007 C011000 10
020 C000001 0
020 C000002 0
020 C000003 0
020 C000004 0
020 C000005 0
020 C000006 0
020 C000007 0
020 C000008 0
020 C000009 0
020 C000010 0
021 000000 0
022 A000001 GOLDMAN SACHS & CO.
022 B000001 13-5108880
022 C000001 13360990
022 D000001 667124
<PAGE> PAGE 2
022 A000002 J.P. MORGAN SECURITIES, INC.
022 B000002 13-3224016
022 C000002 7212260
022 D000002 471802
022 A000003 CS FIRST BOSTON CORP.
022 B000003 13-5659485
022 C000003 4671507
022 D000003 140970
022 A000004 MERRILL LYNCH PIERCE FENNER & SMITH
022 B000004 13-5674085
022 C000004 4404362
022 D000004 36062
022 A000005 LEHMAN BROTHERS INC.
022 B000005 13-2518466
022 C000005 3915245
022 D000005 333947
022 A000006 SANWA SECURITIES (USA) CO., L.P.
022 B000006 13-3046258
022 C000006 3867793
022 D000006 0
022 A000007 CHASE SECURITIES INC.
022 B000007 13-3112953
022 C000007 2924484
022 D000007 397357
022 A000008 BEAR, STEARNS & CO. INC.
022 B000008 13-3299429
022 C000008 2862408
022 D000008 0
022 A000009 MORGAN STANLEY & CO., INC.
022 B000009 13-2655998
022 C000009 2273294
022 D000009 17233
022 A000010 DRESDNER KLEINWORT BENSON NORTH AMERICAN LLC
022 B000010 13-3894311
022 C000010 2233696
022 D000010 0
023 C000000 82346525
023 D000000 2600175
077 A000000 N
078 000000 N
028 A010100 2772989
028 A020100 97620
028 A030100 0
028 A040100 2263396
028 B010100 3138951
028 B020100 101221
028 B030100 0
028 B040100 2663507
028 C010100 2365015
028 C020100 93059
028 C030100 0
<PAGE> PAGE 3
028 C040100 2080592
028 D010100 2834237
028 D020100 105158
028 D030100 0
028 D040100 2043047
028 E010100 3025332
028 E020100 105205
028 E030100 0
028 E040100 3315164
028 F010100 2666256
028 F020100 110568
028 F030100 0
028 F040100 2436985
028 G010100 16802780
028 G020100 612831
028 G030100 0
028 G040100 14802691
028 H000100 0
062 A000100 Y
062 B000100 0.0
062 C000100 28.4
062 D000100 0.0
062 E000100 0.0
062 F000100 22.2
062 G000100 7.9
062 H000100 0.1
062 I000100 36.4
062 J000100 0.0
062 K000100 0.0
062 L000100 4.6
062 M000100 0.0
062 N000100 0.0
062 O000100 0.0
062 P000100 0.0
062 Q000100 0.0
062 R000100 0.4
063 A000100 44
063 B000100 0.0
064 A000100 N
071 A000100 0
071 B000100 0
071 C000100 0
071 D000100 0
072 A000100 6
072 B000100 680530
072 C000100 0
072 D000100 0
072 E000100 0
072 F000100 1774
072 G000100 10518
072 H000100 0
<PAGE> PAGE 4
072 I000100 20273
072 J000100 532
072 K000100 0
072 L000100 344
072 M000100 32
072 N000100 0
072 O000100 917
072 P000100 0
072 Q000100 0
072 R000100 11
072 S000100 0
072 T000100 4116
072 U000100 0
072 V000100 41
072 W000100 0
072 X000100 38558
072 Y000100 0
072 Z000100 641972
072AA000100 102
072BB000100 61
072CC010100 0
072CC020100 0
072DD010100 616191
072DD020100 25781
072EE000100 0
073 A010100 0.0260
073 A020100 0.0270
073 B000100 0.0000
073 C000100 0.0000
074 A000100 0
074 B000100 0
074 C000100 25648250
074 D000100 0
074 E000100 0
074 F000100 0
074 G000100 0
074 H000100 0
074 I000100 2055
074 J000100 0
074 K000100 0
074 L000100 261862
074 M000100 0
074 N000100 25912167
074 O000100 19988
074 P000100 11590
074 Q000100 0
074 R010100 0
074 R020100 0
074 R030100 0
074 R040100 139586
074 S000100 0
<PAGE> PAGE 5
074 T000100 25741003
074 U010100 24978753
074 U020100 762223
074 V010100 1.00
074 V020100 1.00
074 W000100 1.0000
074 X000100 964791
074 Y000100 0
075 A000100 24703431
075 B000100 0
076 000100 0.00
028 A010200 259119
028 A020200 13045
028 A030200 0
028 A040200 241185
028 B010200 293979
028 B020200 13170
028 B030200 0
028 B040200 282390
028 C010200 251592
028 C020200 11982
028 C030200 0
028 C040200 223579
028 D010200 254671
028 D020200 13531
028 D030200 0
028 D040200 207259
028 E010200 336041
028 E020200 13551
028 E030200 0
028 E040200 293196
028 F010200 213668
028 F020200 14224
028 F030200 0
028 F040200 221798
028 G010200 1609070
028 G020200 79503
028 G030200 0
028 G040200 1469407
028 H000200 0
062 A000200 Y
062 B000200 2.3
062 C000200 102.0
062 D000200 1.5
062 E000200 0.0
062 F000200 0.0
062 G000200 0.0
062 H000200 0.0
062 I000200 0.0
062 J000200 0.0
062 K000200 0.0
<PAGE> PAGE 6
062 L000200 0.0
062 M000200 0.0
062 N000200 0.0
062 O000200 0.0
062 P000200 0.0
062 Q000200 0.0
062 R000200 -5.8
063 A000200 42
063 B000200 0.0
064 A000200 N
071 A000200 0
071 B000200 0
071 C000200 0
071 D000200 0
072 A000200 6
072 B000200 87815
072 C000200 0
072 D000200 0
072 E000200 0
072 F000200 231
072 G000200 1501
072 H000200 0
072 I000200 2569
072 J000200 94
072 K000200 0
072 L000200 54
072 M000200 4
072 N000200 0
072 O000200 120
072 P000200 0
072 Q000200 0
072 R000200 4
072 S000200 0
072 T000200 543
072 U000200 0
072 V000200 6
072 W000200 0
072 X000200 5126
072 Y000200 0
072 Z000200 82689
072AA000200 7
072BB000200 1
072CC010200 0
072CC020200 0
072DD010200 82689
072DD020200 0
072EE000200 0
073 A010200 0.0260
073 A020200 0.0000
073 B000200 0.0000
073 C000200 0.0000
<PAGE> PAGE 7
074 A000200 0
074 B000200 50000
074 C000200 3461852
074 D000200 0
074 E000200 0
074 F000200 0
074 G000200 0
074 H000200 0
074 I000200 268
074 J000200 0
074 K000200 0
074 L000200 23177
074 M000200 0
074 N000200 3535297
074 O000200 199883
074 P000200 1623
074 Q000200 0
074 R010200 0
074 R020200 0
074 R030200 0
074 R040200 14138
074 S000200 0
074 T000200 3319653
074 U010200 3319705
074 U020200 0
074 V010200 1.00
074 V020200 0.00
074 W000200 1.0000
074 X000200 140275
074 Y000200 0
075 A000200 3215139
075 B000200 0
076 000200 0.00
SIGNATURE GARY P. SOURA
TITLE MANAGER
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000106830
<NAME> VANGUARD MONEY MARKET RESERVES, INC.
<SERIES>
<NUMBER> 011
<NAME> PRIME PORTFOLIO-INVESTOR SHARES
<MULTIPLIER> 1,000
<CURRENCY> US
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> NOV-30-1997
<PERIOD-START> DEC-01-1996
<PERIOD-END> MAY-31-1997
<EXCHANGE-RATE> 1
<INVESTMENTS-AT-COST> 25648250
<INVESTMENTS-AT-VALUE> 25648250
<RECEIVABLES> 261862
<ASSETS-OTHER> 2055
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 25912167
<PAYABLE-FOR-SECURITIES> 19988
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 151176
<TOTAL-LIABILITIES> 171164
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 25740979
<SHARES-COMMON-STOCK> 24978753
<SHARES-COMMON-PRIOR> 22217807
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 24
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 0
<NET-ASSETS> 24978790
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 680530
<OTHER-INCOME> 0
<EXPENSES-NET> 38558
<NET-INVESTMENT-INCOME> 641972
<REALIZED-GAINS-CURRENT> 41
<APPREC-INCREASE-CURRENT> 0
<NET-CHANGE-FROM-OPS> 642013
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 616191
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 16174705
<NUMBER-OF-SHARES-REDEEMED> 14003222
<SHARES-REINVESTED> 589463
<NET-CHANGE-IN-ASSETS> 2612961
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> (17)
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 1774
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 38558
<AVERAGE-NET-ASSETS> 23740246
<PER-SHARE-NAV-BEGIN> 1.00
<PER-SHARE-NII> 0.026
<PER-SHARE-GAIN-APPREC> 0
<PER-SHARE-DIVIDEND> 0.026
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 1.00
<EXPENSE-RATIO> 0.32
<AVG-DEBT-OUTSTANDING> 0
<AVG-DEBT-PER-SHARE> 0
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000106830
<NAME> VANGUARD MONEY MARKET RESERVES, INC.
<SERIES>
<NUMBER> 012
<NAME> PRIME PORTFOLIO-INSTITUTIONAL SHARES
<MULTIPLIER> 1,000
<CURRENCY> US
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> NOV-30-1997
<PERIOD-START> DEC-01-1996
<PERIOD-END> MAY-31-1997
<EXCHANGE-RATE> 1
<INVESTMENTS-AT-COST> 25648250
<INVESTMENTS-AT-VALUE> 25648250
<RECEIVABLES> 261862
<ASSETS-OTHER> 2055
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 25912167
<PAYABLE-FOR-SECURITIES> 19988
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 151176
<TOTAL-LIABILITIES> 171164
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 25740979
<SHARES-COMMON-STOCK> 762223
<SHARES-COMMON-PRIOR> 910250
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 24
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 0
<NET-ASSETS> 762213
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 680530
<OTHER-INCOME> 0
<EXPENSES-NET> 38558
<NET-INVESTMENT-INCOME> 641972
<REALIZED-GAINS-CURRENT> 41
<APPREC-INCREASE-CURRENT> 0
<NET-CHANGE-FROM-OPS> 642013
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 25781
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 628075
<NUMBER-OF-SHARES-REDEEMED> 799469
<SHARES-REINVESTED> 23368
<NET-CHANGE-IN-ASSETS> 2612961
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> (17)
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 1774
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 38558
<AVERAGE-NET-ASSETS> 963185
<PER-SHARE-NAV-BEGIN> 1.00
<PER-SHARE-NII> 0.027
<PER-SHARE-GAIN-APPREC> 0
<PER-SHARE-DIVIDEND> 0.027
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 1.00
<EXPENSE-RATIO> 0.15
<AVG-DEBT-OUTSTANDING> 0
<AVG-DEBT-PER-SHARE> 0
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000106830
<NAME> VANGUARD MONEY MARKET RESERVES, INC.
<SERIES>
<NUMBER> 02
<NAME> FEDERAL PORTFOLIO
<MULTIPLIER> 1,000
<CURRENCY> US
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> NOV-30-1997
<PERIOD-START> DEC-01-1996
<PERIOD-END> MAY-31-1997
<EXCHANGE-RATE> 1
<INVESTMENTS-AT-COST> 3511852
<INVESTMENTS-AT-VALUE> 3511852
<RECEIVABLES> 23177
<ASSETS-OTHER> 268
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 3535297
<PAYABLE-FOR-SECURITIES> 199883
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 15761
<TOTAL-LIABILITIES> 215644
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 3319739
<SHARES-COMMON-STOCK> 3319709
<SHARES-COMMON-PRIOR> 3100543
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> (86)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 0
<NET-ASSETS> 3319653
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 87815
<OTHER-INCOME> 0
<EXPENSES-NET> 5126
<NET-INVESTMENT-INCOME> 82689
<REALIZED-GAINS-CURRENT> 6
<APPREC-INCREASE-CURRENT> 0
<NET-CHANGE-FROM-OPS> 82695
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 82689
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 1609070
<NUMBER-OF-SHARES-REDEEMED> 1469407
<SHARES-REINVESTED> 79503
<NET-CHANGE-IN-ASSETS> 219172
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 72
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 231
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 5126
<AVERAGE-NET-ASSETS> 3215139
<PER-SHARE-NAV-BEGIN> 1.00
<PER-SHARE-NII> 0.026
<PER-SHARE-GAIN-APPREC> 0
<PER-SHARE-DIVIDEND> 0.026
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 1.00
<EXPENSE-RATIO> 0.32
<AVG-DEBT-OUTSTANDING> 0
<AVG-DEBT-PER-SHARE> 0
</TABLE>