Objective: To find the relationship between parenting styles and undergraduates' mental health from the aspects of positive psychology. Method: 230 undergraduates of China West Normal University were surveyed with the EMBU Scale and College Student Mental Health Scale with a Healthy Personality Orientation. The results suggest that: 1.Concerning parenting styles, parents may take a more stringent rearing to boys and take a gentler rearing to girls; the only children often get more understanding and love from their parents than the children who have siblings; 2. From the level of mental health, boys can control their emotions better than girls; on emotional control and pursuit of goals, science students perform better than liberal and art students; 3. The results of correlation analysis suggest that parents' love and understanding has positive effect on undergraduates' mental health, while punishment, over involvement and rejection have negative effect, besides, parents' preference has no effect on undergraduates' mental health; 4. Regression analysis shows that mothers' love, punishment, strictness and fathers’overprotection have some predictive effect on undergraduates' mental health.