Abstract: ObjectiveTo study the prevalence and related factors of suicidal ideation and depression in undergraduate students in Yinchuan.Methods2 678 undergraduate students were investigated with multistage stratified random clustered samples.Zung Self-Depression Scale(SDS)and self-designed questionnaire were used for depression and suicidal ideation.Results15.4% of respondents had suicidal ideation.The rate of suicidal plan and suicide attempt was 6.6% and 5.6% respectively.40.4% of students had depressive symptoms.Multivariate logistic regression analysis demonstrated that minority, poor cohesion of family and mental quality,intercourse vexation,lower academic achievement and depression were risk factors of suicidal ideaion.Poor cohesion of family,mental quality,intercourse relation and lower academic achievement were risk factors of depression.ConclusionThe prevalence rate of suicidal ideation and depression in undergraduate students in Yinchuan were high.Depression is the major risk factor for suicidal ideaion.