To observe the levels of college students’ moral identity and prosocial behavior, and to explore the effect of parental style, social support on moral identity, and the possible effect mechanism of these three variables on prosocial behavior, Moral Identity Scale, Parental Bonding Instrument, Perceived Social Support Scale, and Prosocial Behavior Scale were used to assess 569 college students. The results indicated that the levels of both moral identity and prosocial behavior were high on the whole, and the correlation between the two characters was moderate, that both parental style and perceived social support could predict moral identity to some extent, that perceived support was mediator factor between paternal style and moral identity, that parental style, perceived support, and moral identity could respectively predict prosocial behavior to some extent, and that moral identity was mediator factor between both parental style and perceived support and prosocial behavior.