For companies and their shareholders, tax is considered one of the expenses and the amount of tax payable is one of the motivating factors in many management decisions. Recent studies of management activities are exclusively aimed at reducing corporate taxes through tax reduction methods. In the current research, the role of social responsibility on the elements of corporate governance and the tax gap in companies listed on the Tehran Stock Exchange has been investigated. The indicators used include the proportion of non-executive directors, institutional ownership and board size. in order to achieve the goal of the research, a sample consisting of 120 companies accepted in Tehran Bahadur Stock Exchange, during the period of 2016 to 2014 (600-years, companies) has been selected and the hypotheses proposed using the model Multivariate regressions (EGLS) were tested. The findings of the research show that there is a direct and meaningful relationship between the ratio of non-executive directors and the tax gap, and this relationship is moderated by applying the role of social responsibility as a moderator. There is an inverse relationship between institutional ownership and the size of the board of directors and the tax gap. There is a significant difference and the inverse relationship is strengthened with the application of social responsibility-moderating variable.