The problem of the abnormal sound of the car body closure seriously affects the ride comfort. In order to solve the prob- lem of rear door shake of a SUV driving on the washboard road, transfer path analysis method was taken in this paper. Vehicle vibration transmission path analysis model was built with theory of transfer path analysis. Combining the measured data with the simulation data, the contribution of each transfer path was analyzed. Results show that lateral thrust rod connection point is the major transfer path for door shake. The optimization scheme of reducing bushing stiffness of lateral thrust rod and increasing the door sealing reaction was adopted through the results of transfer path contribution analysis. By test verification, the optimization scheme can lower door vibration by 63%, which solves the problem of door shake.