Abstract: A power plant mounting structure for a vehicle including an engine-side mount assembly, a transmission-side mount assembly, and front and rear mount assemblies, wherein the engine-side mount assembly includes a mount which is less stiff in the front and rear directions than in the upward and downward directions of the vehicle, and is arranged such that an axis of the mount is parallel to an inertial axis of a moment of inertia of the power plant. Furthermore, it also includes a linkage member for connecting the mount to an engine-side of the power plant by coupling a screw member coaxially fixed at the center of the mount with a screw block fixed to the engine-side of the power plant, and a mounting bracket for fixing the mount to a side member of vehicle body.