WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.

<TABLE> <S> <C>

<ARTICLE> 6
<CIK> 0000320282
<NAME> SMITH BARNEY MUNICIPAL MONEY MARKET FUND, INC.

<S>                             <C>
<PERIOD-TYPE>                   YEAR
<FISCAL-YEAR-END>                          MAR-31-2000
<PERIOD-END>                               MAR-31-2000
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<PAYABLE-FOR-SECURITIES>                       200,000
<SENIOR-LONG-TERM-DEBT>                              0
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<TOTAL-LIABILITIES>                         14,680,588
<SENIOR-EQUITY>                                      0
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<SHARES-COMMON-STOCK>                    7,003,528,026
<SHARES-COMMON-PRIOR>                    7,104,334,497
<ACCUMULATED-NII-CURRENT>                            0
<OVERDISTRIBUTION-NII>                               0
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<DIVIDEND-INCOME>                                    0
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<OTHER-INCOME>                                       0
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<REALIZED-GAINS-CURRENT>                        50,522
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<EQUALIZATION>                                       0
<DISTRIBUTIONS-OF-INCOME>                  193,163,242
<DISTRIBUTIONS-OF-GAINS>                             0
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<NUMBER-OF-SHARES-REDEEMED>             31,453,867,831
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<NET-CHANGE-IN-ASSETS>                   (124,286,180)
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<PER-SHARE-NAV-BEGIN>                             1.00
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<PER-SHARE-NAV-END>                               1.00
<EXPENSE-RATIO>                                   0.63


</TABLE>