Objective To explore the moderation effect of prosocial behavior between life events and depression in adolescents， in order to provide clinical implication for the prevention and treatment of depression among adolescents. Methods From September 2018 to March 2019， 5 491 young students from 6 junior high schools and 3 high schools were selected by stratified cluster sampling method according to the proportion of students and the types of school in a district of Shanghai in the beginning of this year. A self-designed questionnaire on general information， Kutcher Adolescent Depression Scale-11， Adolescent Self-Rating Life Events Check List and Prosocial Behavior Subscale of Strengths and Difficulties Questionnaire were adopted in the test. Moderating effect of prosocial behavior were analyzed by hierarchical regression. Results Correlation analysis indicated that the score of life events was positively correlated with the score of depression （r=0.290， P ＜ 0.05）， and negatively correlated with the score of prosocial behavior （r=-0.183， P ＜ 0.05）. The score of prosocial behavior was negatively correlated with the score of depression （r=-0.475， P ＜ 0.05）. Hierarchical linear regression analysis indicated that the moderating effect of prosocial behavior was statistically significant （β=-0.060， P ＜ 0.05）. At low prosocial behavior， the positive predictive effect of life events on depression is strong （β=0.260， P＜0.01）. At high prosocial behavior， the positive predictive effect of life events on depression was weak （β=0.140， P＜ 0.01）. Conclusions Prosocial behavior could modertae the relationship of life events and depression. With the increase level of prosocial behavior， the effect of life events on depression decrease.