In this paper, optimize the vibrational analysis of power train by decoupling method in the field of automotive. Power train (Engine and gear box) is typically connected to the chassis by three or four rubber mounts. Ideal engine mounts should isolate engine vibrations caused by engine disturbances in the engine speed range and prevent large engine movement from shock excitations from vehicle accelerations, braking and road undulations. The design of power train/mount system involves selection of stiffness coefficients, location and orientation of the individual rubber mounts. Rubber mount location and orientation is decided by designer based on packaging constraints. The goal in this project is to find the engine mount stiffness values corresponding to natural frequencies and mode shapes of the power train system/mount system. CAE find stiffness values and coordinates corresponding to natural frequencies by optimization..