Abstract: Objective To explore the incidence of suicidal ideation in medical students and to evaluate the relations between suicide idea and mental health status and other risk behaviors,and to provide evidence for suicide prevention.Methods Totally 992 students at grades one to three in Shenyang Medical College were sampled using stratified cluster sampling method and were investigated with Adolescent Self-Rating Life Events Check List(ASLEC),Symptom Checklist-90(SCL-90),Social Support Rating Scale(SSRS),and a questionnaire about general information.Results The rate of suicide ideation among the students was 7.1%.The score of negative life events measured by ASLEC for the students having suicidal ideation(45.62±11.71)was significantly higher than that of students without suicidal ideation(38.27±9.08)(t=4.754,P<0.001).The students with suicidal ideation had higher scores for interpersonal factor,academic pressure,enduring punishment factor,and health adaptation factor(all P<0.01) and lower scores for subjective support(19.24±3.57),degree of using-support(6.78±1.72),and total social support(32.85±5.71)(all P<0.05) than those of the students without suicidal ideation.The students with suicide ideation had higher scores for 10 factors in SCL-90 than those of the students without suicide ideation(all P<0.05).Conclusion There was high incidence of suicide ideation in medical undergraduates.Negative life events and poor psychological health are important factors for suicidal ideation among medical students.