Rubbers have a wide range of usage in polymeric materials since materials with a wide variety of mechanical properties can be obtained by varying the type or addition rates of the materials contained in the rubber in addition to the important properties such as high elasticity, good abrasion resistance, and low deformation. Highperformance properties of the material are provided by cross-linking (vulcanization). Raw rubbers do not contain cross-links. In this study, it was aimed to examine the changes that may occur in the mechanical properties of the newly prepared EPDM rubber by changing the composition of the available Ethylene Propylene Diene Monomer (EPDM) rubber. For this purpose, a new rubber mixture, of which composition had been previously known and which was developed in this study, was prepared in two different Banbury mixers (tangential and intermeshing types), and both samples were subjected to mechanical and rheological analyses. The most important criteria in mechanical properties are tensile strength and elongation at break. As these properties increase, the final product becomes more durable. When tensile strength and elongation at break of the EPDM rubber prepared according to the new formulation were compared with the available EPDM rubber, a significant increase was observed in these two values in the EPDM rubber sample prepared with the new formula. In conclusion, it was shown with the characterization analyses that the newly developed modified EPDM rubber can be used in the rubber industry.