Abstarct: The purpose of this study was to determine the relationship between sports participation and sports identity and social capital of cyclists in Mashhad. The sample size was calculated using Cochran formula and 389 people. The cluster random sampling method was used. The present study was descxriptive-analytic by correlation method. Data gathering tool was comprehensive physical activity questionnaire (Ghasemi et al., 2012), Sport Identity (1993), Guyini social capital (2012). Their formal and content validity was reviewed and approved by a group of experts in the field of social sciences and sports management. Cronbach's alpha method was used to calculate the reliability, which was 0.755 for social capital and 0.798 for sports participation and 0.798 for sports identity. In order to analyze the research data, descxriptive statistics (mean, frequency, percentage, standard deviation) and inferential statistics (central limit test, Pearson correlation and confirmatory factor analysis and Sobel test) were used. According to the research findings, there was a relationship between participation in sport with sport identity (r = 0.531), sports participation and social capital (r = 0.467), and social capital with sports identity (r = 0.633). In addition, the results of structural equations showed that the component of sport participation with a coefficient of 0.28 and athletic identity with a coefficient of 0.20 on social capital component had a positive effect on the respondent's view, and the participation component of the sport had a coefficient of 0.89 on the social capital component. Also, Sobel test results showed that sports participation due to sports identity does not have a significant effect on social capital of cyclists in Mashhad. Considering the results obtained as the final conclusion, it can be said that the attempt to strengthen social capital of cyclists in Mashhad can be a valuable strategy for expanding their sports participation.