To improve suspension performance with a simple device by transducing acceleration of a vehicle body to displacement of a rod by means of a weight, first and second coil springs and a damper when vertical speed is increased on a vehicle body, and thereby displacing a guide valve for supplying hydraulic pressure to a cylinder.

When acceleration upward, for instance, is generated on a vehicle body 13, a weight 1 is displaced downward in respect to a sleeve 8, and at the same time a guide valve 4 is displaced downward. Hydraulic pressure is applied to an upper surface of a piston 4 for lifting a cylinder 15, and relative displacement between a tire 16 and the vehicle body 13 is decreased. As a result, downward acceleration is generated on the vehicle body 13, and the initial upward acceleration is canceled. In the case that relative displacement between the vehicle body 13 and the tire 16 is shifted from a neutral position by rolling or the like, a second coil spring 9 is moved by means of a link rod 10. The guide valve 4 is moved, and the piston 14 is moved for returning the relative displacement to the neutral position. The rolling of the vehicle is decreased.