Based on the data of Chinese General Social Survey in 2015,this paper analyses the impact of social capital on the participation of basic medical insurance.The results show that social capital promotes the participation of all residents in health insurance,but the impacts of different types of social capital vary.The impacts of social capital on residents’ participation in medical insurance are in turn social trust,social norms and social networks.At the same time,the impact of social capital on the participation of urban residents differs from that of rural residents.Social norms and social networks can promote the participation of rural residents,but have no significant impact on the participation of urban residents.Social trust has a significant impact on both urban and rural residents’ participation in health insurance,but strangers’ trust affects urban residents and acquaintances’ trust affects rural residents.Therefore,to realize the universal health insurance and the formation of the Chinese-style medical security system in the new era,it is necessary to cultivate good social trust,enhance the actual security effect of medical insurance and innovate the integration path of urban and rural medical insurance.