EXHIBIT 12

STATE STREET CORPORATION

Ratio of Earnings to Fixed Charges

	Three Months Ended March 31, 2004		Years Ended December 31,
(Dollars in millions)			2003		2002			2001		2000		1999
(A) Excluding interest on deposits:
Earnings:
Income before income taxes	$	318	$	1,123	$	1,554		$	944	$	914	$	974
Fixed charges		85		375		506			983		1,360		954
Earnings as adjusted	$	403	$	1,498	$	2,060		$	1,927	$	2,274	$	1,928
Income before income taxes:
Pre-tax income from continuing operations as reported	$	311	$	1,112	$	1,555		$	930	$	906	$	968
Share of pre-tax income (loss) of 50% owned subsidiaries not included in above		7		11		(1	)		14		8		6
Net income as adjusted	$	318	$	1,123	$	1,554		$	944	$	914	$	974
Fixed charges:
Interest on other borrowings	$	56	$	279	$	426		$	881	$	1,268	$	874
Interest on long-term debt, including amortization of debt issue costs		21		78		71			93		82		70
Portion of rents representative of the interest factor in long-term leases		8		18		9			9		10		10
Fixed charges	$	85	$	375	$	506		$	983	$	1,360	$	954
Ratio of earnings to fixed charges		4.74x		4.00x		4.07x			1.96x		1.67x		2.02x
(B) Including interest on deposits:
Adjusted earnings from (A) above	$	403	$	1,498	$	2,060		$	1,927	$	2,274	$	1,928
Add interest on deposits		104		372		498			856		1,012		712
Earnings as adjusted	$	507	$	1,870	$	2,558		$	2,783	$	3,286	$	2,640
Fixed charges:
Fixed charges from (A) above	$	85	$	375	$	506		$	983	$	1,360	$	954
Interest on deposits		104		372		498			856		1,012		712
Adjusted fixed charges	$	189	$	747	$	1,004		$	1,839	$	2,372	$	1,666
Adjusted earnings to adjusted fixed charges		2.68x		2.50x		2.55x			1.51x		1.39x		1.58x