comparative review of relation between the debt ratio and return on assets in various industries

the debt is one of the principal component of accounting equation and capital structure of most companies. during last fifteen years the usage trend of debt was increasingly improved in companies' eps. american ones. in this research we tried to answer the following question: is there any meaningful relation between debt ratio and return on assets (roa) in sec of tehran and its industries? to answer the above mentioned questions debt ratio was analyzed from the view point of current debt, long term debt and total debt in four industries: food and drink industry, machines and equipments industry, automobile & pieces making industry ,tire and plastic industry, using pearson and spearman correlation coefficient. consequently, based on achieved results in all industries there is an inverse relation between debt ratio and roa except in tire & plastic industry. we concluded that companies in our country are not able to use debt well.