Abstract: A one-eighth scale half vehicle lateral active suspension experimental model with four degrees of freedom is established. The active suspension and passive suspension experiments are comparatively studied with LQR control law, and the experimental results is comparied with the simulation results. It is shown that the active suspension can effectively attenuate vibration, especially the vibration at the resonant frequency. Compared with the passive suspension, the amplitudes of the lateral and roll vibrations of the car body are reduced by 80% and 65% respectively on the average at high frequency resonant band in active suspension, and 30% and 25% respectively on the average at the rest of the frequency band.