The main purpose of this research is to examine the independence of the board of directors and the performance of the company in the presence of conservative business strategy in companies listed in Tehran Stock Exchange. Research hypotheses for 1575 years - companies, including all companies listed to the stock exchange after removing holding companies, insurance, leasing, banks, financial and investment institutions that were active during 2015-2021, using Ordinary Least Squares (OLS) regression model, mixed data model was analyzed. In the first model, the independence of the board of directors showed a negative and significant relationship on performance. In the second model regarding the relationship between the independence of the board of directors and the performance of the company in terms of the variable of conservatism strategy, the results showed that the coefficient of the variable of conservatism is negative and significant, which expresses the effect of the variable of conservatism on the relationship between the independence of the board of directors and corporate performance. The results show that independent boards of directors have the ability to objectively monitor and advise management to avoid of managerial opportunism and increase firm's value, which is against the background of agency theory and is consistent with stewardship theory. Then, by adding conservatism as a moderator of the relationship between board independence and firm performance, as a corporate governance mechanism, this study shows that a truly independent board reduces the need for conservatism. In other words, the more conservatism, the less need for board independence. These results are consistent with the theory of stewardship and the theory of resource dependence, which consider responsible managers as more expertise and knowledgeable to make decisions related to increasing the firm's value. Also, involving the conservative strategy in the model increases the coefficient of determination (R2) 20% of the estimated model in approximation.