Purpose: The purpose of this study was to identify impact of stress on depression among university students and the moderating effect of social support in the relationship between stress and depression in university students. Methods: A total of 445 subjects were participated from May to July 2011. Data were collected by self-reported questionnaires and t-test, ANOVA, and stepwise multiple regression with SPSS/WIN 20.0 were used to analyze the data. Results: The results indicate that depression was increased by stress and decreased with social support. Social support included four type of social support behavior; emotional support, informational support, material support, and appraisal support. Multiple regression analysis showed that moderating effect of emotional support was significant when provided by friends but not by parents. Conclusion: These finding indicate the importance of emotional support of friends on depression in university students.