This paper investigated 695 college students by questionnaire survey,and explored the relationships between college students' social goals,moral disengagement and aggressive behavior through concurrent mediation model and longitudinal mediation model.The results show that:1) There are significant gender and grade differences in the level of college students' moral disengagement,boys get significantly higher scores than girls,and the scores of moral disengagement decline with the grade increasing.2) College students' moral disengagement could partially mediate the relationship between social goals and aggressive behavior.3) Moral disengagement plays an important role in the development and stability of college students' social goals.4) There are bidirectional effects between college students' moral disengagement and aggressive behavior.Some countermeasures and suggestions are offered according to the conclusion.