The purpose of this study is To investigate the effect of CEO influence on the relationship between gender composition in board members and the cost of debt of companies listed on the Tehran Stock Exchange. The present study is an applied research booklet in terms of purpose. In terms of the nature of the research, it is part of the review research. In terms of the nature of the data, it is a small research booklet. In order to know the research booklet, it was a semi-experimental method. This method is used when it is not possible to select a company at random or it is not possible to completely manipulate or interfere with independent variables. In terms of descriptive method a) It is a correlational study that multivariate regression has been used. In terms of descriptive method, b) is also a booklet of post-event research. In terms of the type of argument, it is a booklet of deductive-inductive research. In terms of dimension, time is a retrospective research pamphlet. In terms of research duration, it is part of the combined method. The statistical population of the present study is the companies listed on the Tehran Stock Exchange. After removing the restrictions, 128 companies were selected as a statistical sample. The study period is between the years 2013 to 2019. Managers also come to the field to create a large unit in the economy and according to the instructions of Article 1 of the Applied Commerce Law in Iran, companies whose type of obligations are defined in the law and the amount of capital based on its founders or a proportion based on public contributions are formed. Therefore, we seek to investigate the effect of CEO influence on the relationship between gender composition in board members and the debt cost of companies listed on the Tehran Stock Exchange. The results of testing the first hypothesis indicate that there is a direct and significant relationship between gender composition in board members and debt cost. In other words, it can be said that with the increase of gender composition in the members of the board of directors, the cost of debt also increases. Also, based on the test of the second hypothesis, it is stated that the CEO's permeability modulates the relationship between the gender composition of the board members and the cost of the company's debt.