Much research is currently focused on the use of starch as an industrial raw material, which can reduce dependence on non-renewable resources. Pure starches of plants includes 20 -30% of amylose, this value might become to 80% in some starches scarcely, 70-90% amylopectin, approximately 1% fat, protein and minerals. Starches from various sources contain different amounts of amylose and amylopectin, which influence physicochemical properties such as gelatinization, water absorption and paste viscosity. Therefore, amylose/amylopectin (Am/Ap) ratio in starch would effect on physico-mechanical properties of the material which produced from it. The determination of Am/Ap ratio in several samples of starch by a simple modified method was described in this paper and the samples with different Am/Ap ratio were applied as filler in rubber compounds. The physico-mechanical properties of obtaind cure rubbers were investigated. The results showed that the physico-mechanical properties of Natural rubber (NR) compounds filled by various starches are mainly correlated with Am/Ap ratio in the starch samples.