Abstarct: The purpose of this study was to investigate the effect of social responsibility of sports centers on customer loyalty with the mediating role of communication quality. This research, baxsed on the nature and method of doing correlation work, is a type of structural equation, because this research seeks to measure the relation between variables in the form of a causal model. The statistical population of this study included all the female clients of the fitness, aerobics and fitness clubs of Karaj, Iran with 7340 people. The sample was selected in a multi-stage sampling method of 378 people. The research instrument was a researcher-made questionnaire that measured the variables of social responsibility, customer loyalty and communication quality. To analyze the research hypotheses, Pearson correlation tests were used to predict the role and role of predictor variables on the criterion variable through structural equation modeling. Findings of the research showed that direct impact of social responsibility on customer relationship quality was 0.31 which is significant at 0.008, social responsibility of customer loyalty has a significant effect (0.27) at the level of 0.01; The direct effect of customer relationship quality on customer loyalty is 0.22 hundredth, which was significant at 0.01 level and according to the value of Sobel test, which was calculated to evaluate the role of customer relationship quality (more than 1.96) , The assumption is zero and the assumption of the research is confirmed. This means that the quality of communication with customers has a mediating role and social responsibility has a significant effect on customer loyalty due to the quality of customer relationship.