The present study examined developmental changes in children and adolescents of their problematic behaviors. Participants were 458 elementary school children (fifthand sixth-graders), 521 junior high school students (first- and second-graders), and 1,164 high school students (first- and second-graders). They rated the frequency of witnessing, the degree of desiring to experience, and the level of judgment of problematic behaviors on a 6-point scale in each of 24 items regarding three kinds of problematic behaviors; (1) delinquency (e.g., steal things in stores, steal bicycles and things belon ging to others), (2) violence (e.g., beat someone, break windows or doors in a school), and (3) aggression and disturbance (e.g., say mean things topeers, threaten or tease others, disturb in class). The results found three patterns of developmental changes in their witnessing and desiring to experience problematic behaviors. As they become older, boys' and girls' delinquency and boys' violence were generally on the increase, but girls' violence was on the decrease. In contrast, aggression and disturbance showed the inversed-U curves, peaking in junior high school students