To prevent the deterioration in comfortableness to ride in and maneu vering stability of a vehicle even to a fuel quantity change in a fuel tank by providing a fuel detecting means to detect a quantity of fuel in the fuel tank and a control gain variable means to vary a control gain according to a detected fuel quantity.

In a damping force characteristic control means (d), damping force characteristic control of respective shock absorbers (b) is performed on the basis of a vehicle behavior signal of respective wheel positions detected by a vehicle behavior detecting means (c) and a control signal obtained by a prescribed control gain. On the other hand, in a control gain variable means (f), variable control of the control gain is performed according to a fuel quantity in a fuel tank detected by a fuel detecting means (e). Therefore, the occurrence of an overs and shorts condition of control force by an increase-decrease change in a fuel quantity in the fuel tank is prevented by variable control of a damping force characteristic. Therefore, the deterioration of comfortableness to ride in and maneuvering stability of a vehicle can be prevented from damage.