IntroductionProsocial behavior has been shown to be protective against burnout. Yet, we know little about prosocial behavior in medical students. We wanted to know what are chinese medical students' understanding of prosocial behavior and which factors influence their participation in it?MethodsWe undertook a grounded theory study, following Corbin & Strauss. We used convenience sampling and conducted semi-structured individual interviews. We analyzed data using open, axial, and selective coding techniques. Next, we grouped data into concepts. We noticed these concepts aligned with three existing social theories, so we developed our theory in concert with these: the Theory of Planned Behavior, Self-Determination Theory, and Social Support Theory.ResultsTwenty-eight medical students participated in this study. Medical students hold especial views on the roles of medical physicians, and most of these views align with students' core values, including the value of prosocial behavior. Students are intrinsically motivated to engage in prosocial behaviors that align with their core values. Personal values, personality traits, perceived self-competence, career motivation, environmental factors, and family influences are the core factors influencing medically positive prosocial behavior.ConclusionsThis study supports a focus on prosocial behavior instead of altruistic behavior in medical education. We anticipate that promoting prosocial behavior through medical curricula will reduce moral distress and burnout among medical students.