Hardness and tensile properties were selected as effective factors for the rubber vlucanizates in a tire. Simulation system was built for physical properties as the change of each factors by using statistical methods. Correlation and regression analyses were performed by using SAS software for 58 actual factors and 6 variables of response; hardness, tensile strength, 50%-modulus, 100%-modulus. 200%-modulus, and 300% -modulus. Simulation system is composed of 'Forecasting results','Trend analysis,' and 'Result analysis' with graphic user interface (GUI) in order to predict physical properties according to rubber vulcanizates'design before manufacturing and testing them.