[ARTICLE] 6
[CIK] 0000880583
[NAME] THE TRAVELERS SERIES TRUST
[SERIES]
   [NUMBER] 19
   [NAME] MFS RESEARCH PORTFOLIO
<TABLE>
<S>                             <C>
[PERIOD-TYPE]                   6-MOS
[FISCAL-YEAR-END]                          DEC-31-1999
[PERIOD-END]                               JUN-30-1999
[INVESTMENTS-AT-COST]                       80,780,037
[INVESTMENTS-AT-VALUE]                      88,580,028
[RECEIVABLES]                                  718,108
[ASSETS-OTHER]                                       0
[OTHER-ITEMS-ASSETS]                                 0
[TOTAL-ASSETS]                              89,298,136
[PAYABLE-FOR-SECURITIES]                       664,613
[SENIOR-LONG-TERM-DEBT]                              0
[OTHER-ITEMS-LIABILITIES]                      143,117
[TOTAL-LIABILITIES]                            807,730
[SENIOR-EQUITY]                                      0
[PAID-IN-CAPITAL-COMMON]                    78,858,644
[SHARES-COMMON-STOCK]                        7,707,889
[SHARES-COMMON-PRIOR]                        3,587,001
[ACCUMULATED-NII-CURRENT]                       15,921
[OVERDISTRIBUTION-NII]                               0
[ACCUMULATED-NET-GAINS]                      1,786,522
[OVERDISTRIBUTION-GAINS]                             0
[ACCUM-APPREC-OR-DEPREC]                     7,829,319
[NET-ASSETS]                                88,490,406
[DIVIDEND-INCOME]                              229,242
[INTEREST-INCOME]                               83,491
[OTHER-INCOME]                                       0
[EXPENSES-NET]                                 297,624
[NET-INVESTMENT-INCOME]                         15,109
[REALIZED-GAINS-CURRENT]                     2,457,583
[APPREC-INCREASE-CURRENT]                    3,660,488
[NET-CHANGE-FROM-OPS]                        6,133,180
[EQUALIZATION]                                       0
[DISTRIBUTIONS-OF-INCOME]                            0
[DISTRIBUTIONS-OF-GAINS]                             0
[DISTRIBUTIONS-OTHER]                                0
[NUMBER-OF-SHARES-SOLD]                      4,127,330
[NUMBER-OF-SHARES-REDEEMED]                      6,442
[SHARES-REINVESTED]                                  0
[NET-CHANGE-IN-ASSETS]                      50,619,965
[ACCUMULATED-NII-PRIOR]                       (10,432)
[ACCUMULATED-GAINS-PRIOR]                    (659,817)
[OVERDISTRIB-NII-PRIOR]                              0
[OVERDIST-NET-GAINS-PRIOR]                           0
[GROSS-ADVISORY-FEES]                          251,933
[INTEREST-EXPENSE]                                   0
[GROSS-EXPENSE]                                320,162
[AVERAGE-NET-ASSETS]                        59,355,523
[PER-SHARE-NAV-BEGIN]                            10.56
[PER-SHARE-NII]                                      0
[PER-SHARE-GAIN-APPREC]                          00.92
[PER-SHARE-DIVIDEND]                                 0
[PER-SHARE-DISTRIBUTIONS]                            0
[RETURNS-OF-CAPITAL]                                 0
[PER-SHARE-NAV-END]                              11.48
[EXPENSE-RATIO]                                  01.00
[AVG-DEBT-OUTSTANDING]                               0
[AVG-DEBT-PER-SHARE]                                 0
</TABLE>