[Purpose/significance] Under the new situation of the normalization of COVID- 19 epidemic prevention and control, more people are shifting from offline to online medical communities for daily consultation and health management. By analyzing driving factors of knowledge contribution behavior of doctors in online medical communities,this paper aims to provide references for the optimization of health information services for professional medical users in online medical communities. [Method/process] This paper took HaoDf as an example and crawled second-hand data for data analysis. To clarify the driving factors of knowledge contribution behavior of doctors in online medical communities, this paper contextualized structural capital (centrality), cognitive capital (tenure in the field), relational capital (interpersonal reciprocity), and individual motivations (reputation) in online medical communities based on social
capital theory. [Result/conclusion] For structural capital, user centrality does not affect doctors’knowledge contribution behavior significantly.For cognitive capital and individual motivations, tenure in the field and user reputation will both positively and negatively affect doctors’knowledge contribution behavior, depending on doctors’specific type of knowledge contribution behavior.For relational capital, interpersonal reciprocity is the key driver for explaining doctors’knowledge contribution behavior.The interactive effects between structural capital,cognitive capital,relational capital,and individual motivations all affect doctors’knowledge contribution behavior significantly.