A comparative study between group A (those who have attempt) among 999 of senior (second grade) boys and girls was conducted to investigate how such factors as personality, environment, are related to their suicidal attempts. In .the first report, emotional instability and social maladjustment were noticed in group A as to the personality difference, and no marked difference was discriminated as the environmental difference observed in family construction in this study. In the second report, there were some relations among environment, family status, personality and their suicidal attempts, but no relations with economical status of their family. In this report (3), there were several problems to investigate etc. which has remained in (1) ~ (2) reports, and as result, there were a pretty difference between group A and group B.