CORPORATE OFFICE PROPERTIES TRUST AND SUBSIDIARIES EXHIBIT 99.3 RATIO OF EARNINGS TO FIXED CHARGES

For the Six Months Ended For the Year Ended December 31, June 30, ------------------------------------------------------- 2001 2000 1999 1998 1997 1996 ---------- -------- -------- -------- ------- ------- Net Income 8,807 15,134 15,083 4,696 (967) 293 Add: Minority interest -- common units 3,426 6,348 3,457 1,171 65 -- Combined fixed charges & preferred share dividends (per below) 22,456 41,767 29,767 16,446 3,639 1,259 Less: Capitalized interest (per below) (1,933) (3,889) (1,510) (77) -- -- Preferred Share Dividends included in fixed charges (2,494) (3,802) (2,854) (327) -- -- ---------- -------- -------- -------- ------- ------- TOTAL EARNINGS 30,262 55,558 43,943 21,909 2,737 1,552 COMBINED FIXED CHARGES & PREFERRED SHARE DIVIDENDS: Interest 15,956 30,454 21,808 12,207 2,855 1,246 Capitalized interest 1,933 3,889 1,510 77 -- -- Amortization of deferred issuance cost 929 1,382 975 423 64 13 Preferred Share dividends 2,494 3,802 2,854 327 -- -- Series C & Initial Preferred Unit distributions 1,144 2,240 2,620 3,412 720 -- ---------- -------- -------- -------- ------- ------- 22,456 41,767 29,767 16,446 3,639 1,259 Ratio of earnings to combined fixed charges and Preferred Share dividends 1.35 1.33 1.48 1.33 0.75 1.23 Deficiency of earnings N/A N/A N/A N/A (902)(1) N/A

(1) During the year ended December 31, 1997, the Company's net income included a non-recurring expense of $1,353 associated with the termination of an advisory agreement. As a result, earnings were inadequate to cover fixed charges by approximately $902 in the year ended December 31, 1997.