EXHIBIT 11 FIRST KEYSTONE CORPORATION COMPUTATION OF EARNINGS PER COMMON SHARE For the Three Month Period Ended March 31, 2000 1999 (Dollars in Thousands) 2000 1999 Primary Net Income $ 1,158 $ 1,223 Shares Weighted average number of common shares outstanding 2,833,727 2,891,128 Adjustments - increases or decreases None None Weighted average number of common shares outstanding as adjusted 2,833,727 2,891,128 Primary earnings per common share $ .41 $ .42 Assuming full dilution Net Income $ 1,158 $ 1,223 Shares Weighted average number of common shares outstanding 2,833,727 2,891,128 Adjustments - increases or decreases None None Weighted average number of common shares outstanding as adjusted 2,833,727 2,891,128 Earnings per common share assuming full dilution $ .41 $ .42 19