This study is tested the information effects of convertible bond(CB). In orter to examine the abnormal stock returns of convertable day of CB, this study were selected 134 samples for the period from Jan.1988 to Dec.1994. There are some empirical studies which pesent evidents that CB are converted day of CB. The results of empirical study are summarized as follows. As in korea stock market, abnormal stock returns of CB have influenced on convertable day of CB. The day has some affirmative influences but it takes away stock price pressures, the amount of stock and dilution effects. As the results, related corporate stock price falled in preference to market abnormal returns.