Abstract: To solve the serious vibration of a certain light truck cab at about 62 km/h,this paper optimizes the match of the cab-mount system. Frequency response function( FRF) method is used in LMS Test-Lab test system to identify inertial parameters of the cab,such as mass center and inertia. The mass center parameter is then validated by weighting method. Based on these parameters,Genetic algorithm is used in MATLAB program to optimize the stiffness of cab mount. Sample piece is made and road test is carried out to test the improved cab mount. Results show that the vibration amplitude is reduced by 32%,and the ride comfort of the cab is significantly improved.