This study examined whether pubertal development influenced on adolescent aggression directly or this effect was mediated by athletic competence and body satisfaction. The pubertal development was assessed in terms of pubertal status and pubertal timing. Junior high school students (n=551) including 273 girls and 278 boys were asked to complete questionnaires. Main results were as the follows: (1) For girls, at any pubertal status and pubertal timing, athletic competence positively predicted linguistic aggression and negatively predicted hostility. (2) For boys, pubertal status positively predicted hostility. In addition, earlier matured boys showed higher athletic competence and body satisfaction than the counterparts; athletic competence positively predicted physical and linguistic aggression; and body satisfaction positively predicted linguistic aggression and negatively predicted physical aggression and hostility.