Malfasari, EkaMustikasariWardani, Ice Yulia2016-01-092016-01-092016-01-092461-1069wahyu sari yenihttp://repository.unri.ac.id/xmlui/handle/123456789/7734Aggressive behaviour and bullying will be occur when school age children can not achive their normal development task and have no assertiveness ability. The purpose of this study was to identify the effect of TGT and AT to school age development task and their assertiveness ability. The method of this study was a quasy experimental using pre and post test non equivalent control group design. Fifthteen children in 9-12 years old were participated. The childrend were given TGT with 7 session firts, then they were given AT with 5 session After the children are given TGT, development score increase 13 points (mean pre: 40,13 and mean post: 53,13) and assertivness ability increase to 12,93 points (mean pre: 47,93 and mean post: 60,87). After the children are given AT, development score increase to 19,33 point and assertiveness ability increase 13,73 points. After the children was given TGT and AT, emotional development increase to 5,67 points. This therapy can be used for children in community and school to reduce bullying and agressive behaviourenSchool age childrenDevelopmentTerapi Kelompok Terapeutikassertiveness trainingUR-Proceedings