Abstract: ObjectiveTo study the suicide ideation of underg raduates and to explore the relationship between self consistent congruence,mental health and suicide ideation among college students for suicide prevention and intervention.MethodsWith multistage stratified random cluster sampling,768 underg raduates in six colleges were investigated with Self Consistency and Congruence Scale(SCCS),Symptom Checklist-90(SCL-90).ResultsOf the undergraduates investigated 13.21% had suicide ideation.The incidence of suicide ideation of the males(14.0%)was significantly higher than that of the females(12.6%).Students majoring in science had a higher(16.2%)incidence of suicide ideation than that of liberal arts students(10.4%,P<0.05).The level of self consistency and congruence,mental health of the students with the suicide ideation(100.11±9.26,211.30±52.40)was lower than that of students without suicide ideation(90.34±12.14, 143.28±34.59,P<0.001).Regression analysis showed that somatization,depression,self-experience inconsistency and negative self-flexibility,obsessive-compulsive,and terror factor obviously affected suicide ideation.ConclusionImproving of self consistency and congruence and mental health is helpful to prevent suicide ideation among undergraduates.