Abstract
This study examined the effects of eco-system factors on adolescents' suicidal ideation and whether self-esteem and depression mediate in the process to provide theoretical basis for prevention and treatment for problems of adolescents who have suicidal ideation. 2,088 high school students were asked to complete self-administering questionnaires on eco-system factors and adolescents' suicidal ideation. Data were analyzed with frequencies, t-test, ANOVA with Scheffe ad-hoc test, correlation analysis using SPSS 12.0 program and AMOS 5.0 program. Study results were ; First, adolescents' suicidal ideation showed significant differences according to their gender, socio-economic financial status, family structure, and the type of school they attended. Second, self-esteem and depression were proved to have significant mediating effect. Child abuse victimization, subjective school achievement and influence of media coverage of celebrity suicide were most important variables which influenced adolescents' suicidal ideation. These results reinforce importance of understanding adolescents' suicidal ideation with eco-system perspective. Moreover, prevention programs for adolescents' suicide require differentiated strategies and tactics according to the target group characteristics.