Abstract Prosocial behavior acting as a precondition for shaping ideal interpersonal relationships, is curial in the development of a person’s social competence. This study examined the association between empathy and prosocial behavior in a sample of 1171 adolescents in China. An empathy questionnaire, social support rating scale, and helping attitude scale were applied in the study. Empathy had an influence on prosocial behavior through social support as a mediating factor. The mediating effect of social support between empathy and prosocial behavior was mainly manifested through perceived social support. The current findings imply that cultivating the empathy of adolescents and promoting their perceived social support may be effective to enhancing their prosocial behavior.