Involvement theory is applied in this study to explore the effects of Taiwanese junior college students´ campus involvement on depressive mood. The research aims to explore the relationships among personal factors, academic involvement, interpersonal involvement and depressive mood in university. The samples are drawn from the survey of juniors of 2005 academic year in the Taiwan Integrated Postsecondary Education Database (TIPED), in which a total of 23,700 are included in the sample. By using Structural Equation Model (SEM), the results show that the influence of personal factors on academic involvement, interpersonal involvement, and depressive mood, and academic involvement on interpersonal involvement and depressive mood, and interpersonal involvement on depressive mood are evident. Furthermore, academic involvement and interpersonal involvement have a significant mediating effect on the relationship between personal factors and depressive mood; and interpersonal involvement has a significant mediating effect on the relationship between academic involvement and depressive mood. Implications for educational practices and future research were discussed.