Choosing the financial supply is one of the most important decisions for providing optimal structure that can be effective for firm value and stocks market of companies. Therefore, marketing as one of the abilities of the firm can be effective on firm function. The purpose of this research is studying the role of marketing intensity on the relation of financial leverage and firm function in Companies listed on the Tehran Stock Exchange. This study is performed between 2012 and 2016 and 103 firms are studied in this research. The independent variables in this research are financial leverage and marketing intensity. The dependent variable is firm evaluation that Tobin's Q is used for evaluating this variable. For evaluating the research variables, Eviews 9 software is applied. The research findings illustrate there is not a U relation between financial leverage and firm function and marketing intensity is not a moderator between these two variables.