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

<TABLE> <S> <C>

<ARTICLE> 6
<CIK> 0000862502
<NAME> New York Municipal Money Market Fund
<SERIES>
   <NUMBER>002
   <NAME>Salomon Brothers Investment Series

<S>                             <C>
<PERIOD-TYPE>                  6-MOS
<FISCAL-YEAR-END>                               Dec-31-2000
<PERIOD-END>                                    Jun-30-2000
<INVESTMENTS-AT-COST>                           145,654,500
<INVESTMENTS-AT-VALUE>                          145,654,500
<RECEIVABLES>                                       498,439
<ASSETS-OTHER>                                    1,291,207
<OTHER-ITEMS-ASSETS>                                      0
<TOTAL-ASSETS>                                  147,444,146
<PAYABLE-FOR-SECURITIES>                                  0
<SENIOR-LONG-TERM-DEBT>                                   0
<OTHER-ITEMS-LIABILITIES>                           626,068
<TOTAL-LIABILITIES>                                 626,068
<SENIOR-EQUITY>                                           0
<PAID-IN-CAPITAL-COMMON>                        146,991,729
<SHARES-COMMON-STOCK>                             5,093,925
<SHARES-COMMON-PRIOR>                             5,818,342
<ACCUMULATED-NII-CURRENT>                                 0
<OVERDISTRIBUTION-NII>                                    0
<ACCUMULATED-NET-GAINS>                            (173,651)
<OVERDISTRIBUTION-GAINS>                                  0
<ACCUM-APPREC-OR-DEPREC>                                  0
<NET-ASSETS>                                    146,818,078
<DIVIDEND-INCOME>                                         0
<INTEREST-INCOME>                                 3,169,934
<OTHER-INCOME>                                            0
<EXPENSES-NET>                                      316,497
<NET-INVESTMENT-INCOME>                           2,853,437
<REALIZED-GAINS-CURRENT>                                  0
<APPREC-INCREASE-CURRENT>                                 0
<NET-CHANGE-FROM-OPS>                             2,853,437
<EQUALIZATION>                                            0
<DISTRIBUTIONS-OF-INCOME>                            98,330
<DISTRIBUTIONS-OF-GAINS>                                  0
<DISTRIBUTIONS-OTHER>                                     0
<NUMBER-OF-SHARES-SOLD>                           1,308,308
<NUMBER-OF-SHARES-REDEEMED>                       2,127,458
<SHARES-REINVESTED>                                  94,733
<NET-CHANGE-IN-ASSETS>                          (27,984,325)
<ACCUMULATED-NII-PRIOR>                                   0
<ACCUMULATED-GAINS-PRIOR>                          (173,651)
<OVERDISTRIB-NII-PRIOR>                                   0
<OVERDIST-NET-GAINS-PRIOR>                                0
<GROSS-ADVISORY-FEES>                               202,181
<INTEREST-EXPENSE>                                        0
<GROSS-EXPENSE>                                     316,497
<AVERAGE-NET-ASSETS>                              5,518,879
<PER-SHARE-NAV-BEGIN>                                 1.000
<PER-SHARE-NII>                                       0.018
<PER-SHARE-GAIN-APPREC>                               0.000
<PER-SHARE-DIVIDEND>                                  0.018
<PER-SHARE-DISTRIBUTIONS>                             0.000
<RETURNS-OF-CAPITAL>                                  0.000
<PER-SHARE-NAV-END>                                   1.000
<EXPENSE-RATIO>                                        0.39



</TABLE>