Abstract: SCL-90, the Ways of Coping-Revised Scale, the Social Support Revised Scale, Adolescent Self-rating Life Events Checklist and Self-designed Questionnaire on Suicidal Behavior including suicidal ideation and suicide attempts were used to study the suicidal behavior and its related factors among 3313 college undergraduates in Yunnan Province.The results showed: (1) 427 (13.2%) undergraduates had suicidal ideation, which female's number were significantly more than male in Chi-square test; And 154 (4.7%) undergraduates had suicide attempts, but there were no significant different between female and male; (2) Suicidal behavior had significant different in demographic variables, which female, singleton, liberal students, the students from city and incomplete family had significant high suicidal ideation score than corresponding students, and only the students from city and incomplete family had significant high suicidal attempt score than corresponding students; (3) Suicidal ideation and suicide attempts was positively related to emotion-focused coping, life events and mental healthy problems, but negatively related to problem-focused coping and social support; (4) In the SEM, Social Support could be moderate variable between mental health and suicidal behavior, and coping could be mediate variable between life events, social support, interaction of mental health and social support, interaction of life events and social support and suicidal behavior.

Key words: undergraduates, suicidal ideation, suicide attempt, related factors