Adolescent period is very important because they experience confusion by a sudden change. Adolescents ought to be bright and healthy but because of social problems they show depression, stress, family relationship, school violence, even suicide. The purpose of this study is to investigate the factors affecting adolescents' suicide and to provide solutions. According to various literatures and condition study, depression, stress, family relationship and school violence proved a primary suicide factors. In order to prevent these adolescents' suicide, personal, family, school, and social approach is required. A proposal on this study is as follows. First, suicide preventive education in school and physical effort will be required. Second, counsel and program development for depress, stress and family relationship will be required. Third, emotional base of support will be required.