EXHIBIT 12

                            STATE STREET CORPORATION

                       RATIO OF EARNINGS TO FIXED CHARGES



- ------------------------------------------------------------------------------------------------------------------------
                                                   Nine Months
                                                      Ended                     Year Ended December 31,                
                                                  September 30,  -------------------------------------------------------
(Dollars in millions)                                 1997           1996       1995       1994       1993       1992
- ------------------------------------------------------------------------------------------------------------------------
                                                                                                 
(A) Excluding interest on deposits:
Earnings:
      Income before income taxes.................... $  420       $    453    $    370     $ 343      $ 292      $ 271
      Fixed charges.................................    452            477         495       267        184        190
                                                     ------       --------    --------     -----      -----      -----
           Earnings as adjusted..................... $  872       $    930    $    865     $ 610      $ 476      $ 461
                                                     ======       ========    ========     =====      =====      =====
Income before income taxes
      Pretax income from continuing
        operations as reported...................... $  417       $    447    $    366     $ 340      $ 291      $ 271
      Share of pretax income of 50% owned
        subsidiaries not included in above..........      3              6           4         3          1          -
                                                     ------       --------    --------     -----      -----      -----
           Net income as adjusted................... $  420       $    453    $    370     $ 343      $ 292      $ 271
                                                     ======       ========    ========     =====      =====      =====
Fixed charges:
      Interest on other borrowings.................. $  404       $    452    $    482     $ 254      $ 170      $ 173
      Interest on long-term debt including
        amortization of debt issue costs............     40             15           9         9         10         13
      Portion of rents representative of the
        interest factor in long term lease..........      8             10           4         4          4          4
                                                     ------       --------    --------     -----      -----      -----
      Fixed charges................................. $  452       $    477    $    495     $ 267      $ 184      $ 190
                                                     ======       ========    ========     =====      =====      =====
Ratio of earnings to fixed charges..................   1.93x          1.95x       1.75x     2.29x      2.59x      2.43x

(B) Including interest on deposits:
      Adjusted earnings from (A) above.............. $  872       $    930         865     $ 610      $ 476      $ 461
      Add interest on deposits......................    363            425         416       281        214        263
                                                     ------       --------    --------     -----      -----      -----
           Earnings as adjusted..................... $1,235       $  1,355    $  1,281     $ 891      $ 690      $ 724
                                                     ======       ========    ========     =====      =====      =====
Fixed charges:
      Fixed charges from (A) above.................. $  452       $    477         495     $ 267      $ 184      $ 190
      Interest on deposits..........................    363            425         416       281        214        263
                                                     ------       --------    --------     -----      -----      -----
           Adjusted fixed charges................... $  815       $    902    $    911     $ 548      $ 398      $ 453
                                                     ======       ========    ========     =====      =====      =====

Adjusted earnings to adjusted fixed charges.........   1.52x          1.50x       1.41x     1.63x      1.74x      1.60x