Objective: This study aimed to examine the mediating effect of depression on hope and suicide ideation, and to explore the relationship among depression, hope and suicide ideation.Methods: Self-Rating Depression Scale (SDS), Dispositional Hope Scale (DHS) and SCL-90 were administered as part of a psychological health screening study for 4843 college students in a university in Hubei Province.T-test, multivariate logistic regression and pathway analysis were conducted to explore the association among hope, depression and suicide ideation.Results: Suicide rate of college students was 4.9%.There were significant differences in depression (t=-18.63, P≤0.05), agency of the HOPE (t=11.26, P≤0.05), and pathway of the HOPE (t=-9.78, P≤0.05) between students with suicide ideation and those without suicide ideation.The SDS score of depression of students with suicide ideation was significantly higher than that of the students without suicide ideation.The DHS score of hope of students with suicide ideation was significantly lower than that of the students without suicide ideation.Comparing with the male, the female students had higher SED score and were more likely to have suicide ideation.In the pathway analysis, it suggested that the data fitted the model well (X2=4.217, df=3, CFI=0.99, TLI=0.99, RMSEA=0.009, WRMR=0.416).The interaction of the agency of HOPE and depression has negative effect on the suicide ideation.Agency component of hope had significantly negative effects on later depression.Pathway of HOPE had effect on suicide ideation via depression, while depression had positive effect on suicide ideation.Conclusion: Hope can decrease the level of depression and the probability of suicide ideation.Depression is the mediator for hope and suicide ideation.Hope has an effect on suicide ideation via depression.Female students are inclined to have higher level of depression and more likely to have suicide ideation.