<TABLE> <S> <C>

<ARTICLE> 6
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE JOHN
HANCOCK VARIABLE SERIES TRUST I SEMIANNUAL REPORT DATED JUNE 30, 1999 AND IS
QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL STATEMENTS.
</LEGEND>
<SERIES>
   <NUMBER> 01
   <NAME> LARGE CAP GROWTH
<MULTIPLIER> 1000

<S>                             <C>
<PERIOD-TYPE>                   6-MOS
<FISCAL-YEAR-END>                          DEC-31-1999
<PERIOD-START>                             JAN-01-1999
<PERIOD-END>                               JUN-30-1999
<INVESTMENTS-AT-COST>                          885,212
<INVESTMENTS-AT-VALUE>                       1,236,819
<RECEIVABLES>                                      697
<ASSETS-OTHER>                                       0
<OTHER-ITEMS-ASSETS>                                 0
<TOTAL-ASSETS>                               1,237,516
<PAYABLE-FOR-SECURITIES>                         1,705
<SENIOR-LONG-TERM-DEBT>                              0
<OTHER-ITEMS-LIABILITIES>                          157
<TOTAL-LIABILITIES>                              1,862
<SENIOR-EQUITY>                                      0
<PAID-IN-CAPITAL-COMMON>                       763,411
<SHARES-COMMON-STOCK>                           42,617
<SHARES-COMMON-PRIOR>                                0
<ACCUMULATED-NII-CURRENT>                           38
<OVERDISTRIBUTION-NII>                               0
<ACCUMULATED-NET-GAINS>                        128,740
<OVERDISTRIBUTION-GAINS>                             0
<ACCUM-APPREC-OR-DEPREC>                             0
<NET-ASSETS>                                 1,235,654
<DIVIDEND-INCOME>                                3,982
<INTEREST-INCOME>                                  352
<OTHER-INCOME>                                       0
<EXPENSES-NET>                                   2,408
<NET-INVESTMENT-INCOME>                          1,926
<REALIZED-GAINS-CURRENT>                       128,740
<APPREC-INCREASE-CURRENT>                      (6,620)
<NET-CHANGE-FROM-OPS>                          124,046
<EQUALIZATION>                                       0
<DISTRIBUTIONS-OF-INCOME>                      (1,926)
<DISTRIBUTIONS-OF-GAINS>                             0
<DISTRIBUTIONS-OTHER>                                0
<NUMBER-OF-SHARES-SOLD>                          3,115
<NUMBER-OF-SHARES-REDEEMED>                    (3,584)
<SHARES-REINVESTED>                                 70
<NET-CHANGE-IN-ASSETS>                         108,890
<ACCUMULATED-NII-PRIOR>                              0
<ACCUMULATED-GAINS-PRIOR>                            0
<OVERDISTRIB-NII-PRIOR>                              0
<OVERDIST-NET-GAINS-PRIOR>                           0
<GROSS-ADVISORY-FEES>                            2,119
<INTEREST-EXPENSE>                                   0
<GROSS-EXPENSE>                                  2,408
<AVERAGE-NET-ASSETS>                                 0
<PER-SHARE-NAV-BEGIN>                            26.19
<PER-SHARE-NII>                                    .04
<PER-SHARE-GAIN-APPREC>                           2.80
<PER-SHARE-DIVIDEND>                             (.04)
<PER-SHARE-DISTRIBUTIONS>                            0
<RETURNS-OF-CAPITAL>                                 0
<PER-SHARE-NAV-END>                              28.99
<EXPENSE-RATIO>                                    .41


</TABLE>