This study assessed the effects of a psychoeducational program designed for improving the social adaptability of social information-processing among young adolescents. A total of 213 junior high-school students (male=105, female=108; ages 12 to 13) participated in this study. The program consisted of a five session social competence educational intervention based on the psychoeducational components of the Social Life (Yoshida , Hirooka, & Saito, 2002, 2005), and the EQUIP programs (Gibbs, Potter, & Goldstein, 1995), conducted as part of regular classes. Findings indicated a significant improvement in the adaptability of social information-processing, as viewed from the causal model suggested by Yoshizawa & Yoshida (2004). The intervention, however, did not show any concurrent inhibition effects on socially delinquent behavior tenden­ cies (SDBT). The results were discussed with respect to the possibility of a time lag in the effects from information-processing to SDBT, and of a developmentally intensified period in their antisocial tendency during this program. Further, we discussed the need to adapt a lengthier or time-unlimited program, with instructors who have mastered the required teaching skills for such a program.