BACKGROUND: Suicide is a self-destructive behavior that can occur throughout life. Recently the suicide rate has gradually increased in Korea. Suicide is the third most common cause of death in adolescents. The most important factOrs closely related to suicide were depression and hopelessness. This study aimed to analyze first, relationships between suicidal ideation, depression, hopelessness, social support and self-esteem, second, the differences between the demographic factors and suicidal ideation, depression, hopelessness, social support and self-esteem. METHODS: This study was surveyed with a questionaire to 220 students of colleges located in Pusan. The instruments were used in this study were Harters(1988) Self-Perception Profile for College Students, Harter and Robinsons(1988) Approval Support Scale for Adolescents, Becks(1961) Beck Depression Inventory, Becks(1974) Beck Hopelessness Scale and Reynolds(1987) Suicidal ideation Questionaire. RESULTS: Self-esteem had a relatively strong positive correlation with social support. Suicidal ideation had a strong positive correlation with depression. Depression had a negative correlation with self-esteem and social support. Suicidal ideation had a negative correlation with self-esteem and social support. CONCLUSIONS: According to this study, the major factors related to suicidal tendency of adolescents were depression, low self-esteem, and low social support. Then the strategy to improve self-esteem and to encourage social support should be implemented for adolescents to prevent suicide.