The firm value is very important for shareholders, investors, managers, creditors and other stakeholders in assessing the future of the company and its impact on estimating the risk and return on investment and stock prices. Therefore, it will be useful to identify the factors that affect the firm value. Social responsibility reporting is related to the economic, ethical, social and environmental aspects of the company. For this reason, it is important to note whether shareholders use the social responsibility reporting information in the data set to value the stock. Based on the above, the purpose of this study is to investigate the effect of social responsibility on the firm value with the adjusting role of family ownership in companies listed on the Tehran Stock Exchange. In order to achieve the above objectives, two hypotheses were formulated. Therefore, in order to test the research hypothesis, a sample of 100 firms was selected from the firms listed in Tehran Stock Exchange during the period 2012 to 2019. Multivariate regression model based on combined data was used to test the research hypothesis. The results of this study show that there is a positive relationship between corporate social responsibility and firm value, which means that with increasing corporate social responsibility, firm value will increase; In addition, family ownership affects the relationship between social responsibility and firm value.