Abstract: Objective To investigate the characters of prosocial behavior and the relationship between prosocial behavior and network of social support among vocational students.Methods Totally 575 vocational students were tested with Prosocial Behavior Questionnaire and Network of Social Support Questionnaire.Results The prevalences of prosocial behavior from high to lowwere helpfulness(3.85±0.59),cooperation(3.62±0.57),sharing with others(3.61±0.57),and comfort(3.20±0.45) among the students.Compared with the male students,female students showed more help and cooperative behavior(P < 0.01).Different types of the social support had a close relationship with prosocial behavior except comfort behavior.The social support from friend showed a positive predictive role to behaviors of help and sharing with others; the degree of satisfaction to friend showed a positive predictve role to cooperation behavior; the closeness with friend showed a positive predictive role to comfort behavior; the companion support from friend showed a negative predictive role to comfort behavior; the companion support from teacher showed a positive predictive role to comfort behavior; the conflict and punishment from teacher showed a negative predictive role to help behavior; the support from father and mather showed no significant predictive role.Conclusion High social support,high degree of satisfaction to friend,strong closeness with friend,and high companion support and lowconflict and punishment from teacher are important promotive factors for prosocial behavior among vocational students.