In this study the effect of "Financial Leverage (FL) on Earning Response Coefficient (ERC)" for accepted members of Tehran Stock Exchange is considered. The purpose is to find out whether or not the investors, analysts, etc. consider the capital structure and leverages of the firms when reacting to the good and bad news caused by revealing the accounting in formation. Financial Leverage measurement approaches are of two divisions as follows: I) Income Statement 2) Balance sheet In this research balance sheet approach i s used. In this approach, two definitions have been considered for leverage. I) Debit/ assets Ratio 2) Debit I equity Ratio Both definitions are used here. Studying the only research hypotheses using the regression analysis during 2000-20004 indicates that in the first leverage definition there is a reverse relationship between FL & ERC in the whole sample and in high leverage and in the second definition i n high leverage. However in the first definition in low leverage and i n the second one in the whole sample and in low leverage there's no considerable relationship between ERC and FL.