The necessity of success and sound performance of companies is the existence of a strong corporate governance structure to better monitor management and use conservatism to improve financial performance. Present study investigates the effect of corporate governance and political connections on accounting conservatism of companies of listed companies in Tehran Stock Exchange. The statistical sample of the study is collected by systematic deletion from the companies listed in Tehran Stock Exchange during the period of 2013 to 2020, the size of which is 140 firms. To test the research hypothesis pooled data regression method is used. The results of the research hypothesis test indicate that the board size does not have a significant positive effect on accounting conservatism. Board independence, audit quality and management ownership have a positive and significant effect on accounting conservatism of companies listed companies in Tehran Stock Exchange. Also the results show that government ownership and political connections have a negative and significant effect on accounting conservatism in firms listed in Tehran Stock Exchange.