Objective To explore the effect of coping style and social adjustment on mental health of undergraduates.Methods A large sample investigation was operated on undergraduates in Fuzhou.Linear correlation and regression analysis and structural equation analysis were used in explosing of the effect of coping style and social adjustment on mental health of undergraduates.Results A 38.9% variance of meatal health could be explained by active and negative coping style,objective and subjective social adjustment.Active and negative coping style demonstrated respectively 59.3%,46.7% indirect effect of total effect through social adjustment on mental health.Conclusion To advocate active coping style and improve college social adjusment were good for the promotion of mental health.