The polymer composites of EVA, LDPE and fillers (CaCO3, kaolin, talc and BaSO4) were investigated. The EVA, LDPE and fillers in verious compositions such as 30/5/65, 25/5/70 and 20/5/75 were mixed in two-roll mill to make 2 milimeters thickness sheets. The study revealed the effect of type and filler content, VA content on mechanical properties of polymer composites. The mechanical properties were determined by using tensile testing and hardness Shore A testing. The tensile strength and ultimate elongation were tested in 2 directions; machine direction (MD) and transverse direction (TD). The tensile strength and ultimate elongation of polymer composite decreased while their hardness increased when filler contents were increased from 65 to 75%. The increasing of VA contents from 18 to 22% caused the tensile strength and hardness to decrease but the ultimate elongation increased. The best composition of polymer composite for mass back was EVA(N8038)/LDPE/talc at 30/5/65. The tensile strength in MD and TD, the ultimate elongation in MD and TD and the hardness Shore A were 441.3 psi, 418.3 psi, 459.0%, 438.3% and 83.3, respectively for the prepared polymer composites, meanwhile, the correspending values of the commercial resins in the above criteria were>300 psi, >200 psi, >400%, >350% and 75-85, respectively. It was noted that the mechanical properties of prepared polymer composites were in acceptable range of commercial resin. Moreover, this polymer composite was very low cost.