The present study examined the effects of schoolwide social skills training program in junior high school. 247 students participated in this program. Classroom-based social skills training was implemented by the classroom teachers. The training consisted of three sessions which focused on three target skills : greeting, active listening, and warm message. The training procedure comprised instruction, modeling, rehearsal, feedback, and homework. Results indicated improvements in target skills. However, the negative effects were found on satisfaction with school life scale. The findings were discussed in terms of the context of training and methodological issues.