Tax is one of the primary sources of government revenue which is a principal part of the government budget and is considered an inevitable part of corporate payments. The Board of directors is one of the chief decision-making groups in determining corporate tax avoidance. Therefore, the relationships seen in the form of a social network between the board members of various companies can affect the tax policy of companies. The primary purpose of this study is to examine the structure of relationships between companies based on their joint board members and to detect the relationship between the companies position in the network of board members' relations with their tax planning activities. The statistical population of this research was all companies listed on the Tehran Stock Exchange from 2011 to 2020. The social network analysis approach developed on graphic techniques based on graph theory and regression analysis was used to conduct the research analysis. The research results show that some companies active in the Tehran Stock Exchange have a better position than other companies in the network. In addition, evidence showed that the status and position of companies in the network of relationships could affect the extent of their tax avoidance.