The negative impacts of aggressive bullying behavior by adolescents on both the bullies and victims are being increasingly recognized as social and economic problems. At the same time, there are alarming trends in face-to-face and online aggression and bullying behavior in Hong Kong. Since the 1970s, prevention and intervention programs to reduce bullying behavior have been implemented in schools in Western countries; however, antibullying and antiaggression programs in Hong Kong schools only began in the 2000s. There are two ways of defining the target groups for these intervention programs. Programs using a one-factor model categorize the adolescents who exhibit bullying behavior into a single group, bullies, whereas two-factor models distinguish two subtypes of aggression: reactive and proactive aggression. The former approach is emphasized in the Restorative Whole-school Approach with Shared Concern method, which uses mediation to reduce bullying in schools. The two-factor approach differentiates adolescents' behaviors into reactive, proactive, or occurring reactive-proactive aggression based on the functions and underlying goals of their actions. Specific interventions are then designed to address the particular features and psychosocial correlates of reactive and proactive aggression. The aim is to develop the positive development attributes related to specific types of aggression and thus reduce aggressive behavior in schools.