PURPOSE: To improve riding comfort in the whole vehicle speed region by selecting a forecast control means in the vehicle speed less than set vehicle speed and an active control means in the set vehicle speed or more on the basis of the road surface information in front of wheels to be controlled and vertical acceleration.

CONSTITUTION: The operative pressure of hydraulic cylinders 18FL-18RR interposed between a car body side member 10 and wheels 11FL-11RR side member 14 is controlled by pressure controlling valves 20FL-20RR according to the command of a controller 30. The controller 30 inputs the signals of a vehicle speed sensor 26 and vertical acceleration sensors 28FL-28RR corresponding to respective wheels 11FL-11RR to compare the vehicle speed V with the set vehicle speed Vs from a detecting value in every predetermined sampling time. Here, forecast control for the rear wheel side pressure controlling valves 20RL, RR is carried out according to the driving condition of the front wheels in V<Vs, and the pressure controlling valves 20FL-20RR is actively controlled to restrain the vertical movement of the car body in V≥Vs, so that the riding comfort can be improved in the whole vehicle speed region.