It is caused that combustion performance of engine is increasing effects according to the controling back pressure. Therefor, Exhaust variable valve is installed around the automation silencer. After the exhaust variable has analysed with the reckoning stress distribution to affect in valve, the design factor was analysed with influence. Therefor, It has to translate between the conditions an variables. After results, the distribution of pressure has been indicated when it have condition on the convex face. The distribution was indicated the most alike as pressure and stress that diameter about 42mm and depth to height 5mm in model between the stress and strain. If this interpretation of using it. That’s possible to reduce the time and cost about a valuation.