The purpose of this study was to investigate the difference of adolescent self-conscious emotion, empathy, forgiveness and prosocial behavior across gender and grade, to analyze the difference between the correlations among prosocial behavior and other variables across gender and grade, and to investigate the effects of adolescent self-conscious emotion, empathy, forgiveness on prosocial behavior in each gender and grade group. The subjects were 272 adolescents who were recruited by purposive sampling in the Chungbuk area. The results indicated that the empathy of girls was higher than that of boys. Boys showed a stronger correlation between prosocial behavior and guilt than girls. Next, boys' prosocial behavior was predicted by cognitive empathy, guilt, and pride, whereas girls' prosocial behavior was predicted by forgiveness toward others, pride, cognitive empathy and emotional empathy. Last, middle school students' prosocial behavior was predicted by pride and guilt, whereas that of high school students' was predicted by cognitive empathy, guilt, pride, and forgiveness toward others and the situation. In conclusion, self-conscious emotions, empathy, and forgiveness all predicted adolescent prosocial behavior but in different ways across gender and grade. It implies that adolescents need diverse educational programs according to their gender and grade, to promote their self-conscious emotions, moral emotions, and prosocial behavior.