In order to identify the effects of price behavior by reducing capital to make up a lose and stock repurchases, the investment performance of listed firms from January 1, 2001 to June 30, 2003 are examined by event study. It is indicated that capital decrease according to Corporate Regulation to make up a loss are associated with negative return but not significantly. On the other hand, the long-term investment performances of capital reducing firms according to Security Transaction Regulations do not show abnormal returns. However, the performances of capital reducing firms according to Security Transaction Regulation are better than those according to Corporate Regulation.