This study The relationship between Financial Leverage and Conservatism With behavior of the firm's investment pays. Changing Financial Leverage the ratio of total liabilities to total assets and for changing conservative policy the model of conditional conservatism the by and and Dvlman and Ahmad (2007), inspired by the model Gyvly and Hine (2000) proposed tothe use is. In order to examine the 107 companies listed in Tehran Stock Exchange, during the years 2010 to 2014 examined were . Results using a multivariate regression model and panel data, Indicates negative relationship between between Financial Leverage and inefficient investment and also negative relationship between Conservatism and and inefficient investment is.