Abstract: This study was to examine whether dependency personality and self-criticism personality were mediators or moderators on the relationship between stress and depression. A total of 634 undergraduates completed General Social and Academic Hassles Scale (GSAHS), Center for Epidemiologic Studies Depression Scale (CES-D) and Depressive Experiences Questionnaire (DEQ). Stepwise regression and hierarchical multiple regression were used to explore whether the dependency and self-criticism were moderators or mediators. The results showed that there were positive correlations among scores of GSAHS, CES-D, dependency factor of DEQ, self-criticism factor of DEQ. Moreover, subjects with high dependency and self-criticism had significantly higher scores in GSAHS and CES-D than those with low dependency and self-criticism. Regression analyses showed that both dependency and self-criticism were part mediators rather than moderators on the relationship between stress and depression. This study demonstrated that personalities of dependency and self-criticism were mediators on the relationship between stress and depression in undergraduates.