The purpose of present study is to investigate the relationship between voluntary disclosure of extensible financial reporting language and stock market valuation and the role of corporate governance in companies listed on the Tehran Stock Exchange. For this purpose, 140 companies during the period 2014-2019 were surveyed. In this research, the information related to the variables was extracted from Rahavard 3 software and was summarized, classified, calculated by Excel software and finally hypotheses tested by Eviews and stata software at a confidence level of 0. 95. The findings of the first hypothesis showed that there is a significant and positive relationship between voluntary disclosure of extensible financial reporting language and stock market valuation in companies. Also, the findings of the second hypothesis showed that there is a significant and positive relationship between corporate governance and stock market valuation in companies. In addition, the findings of the third hypothesis showed that corporate governance has a positive and significant effect on the relationship between voluntary disclosure of extensible financial reporting language and stock market valuation in companies.