A suspension system for a motor vehicle includes a shock absorber having a device for allowing a change in a damping-force characteristic, a first sensor for sensing a vertical behavior of the motor vehicle, a second sensor for sensing a roll angle of the motor vehicle during steering operation, a third sensor for sensing a roll rate of the motor vehicle during steering operation, and a control unit. The control unit includes a fundamental control part for carrying out an ordinary control of the damping-force characteristic of the shock absorber in accordance with the vertical behavior as sensed, a first roll restraining control part for carrying out a first roll restraining control in place of the ordinary control when the roll angle as sensed is equal to or greater than a predetermined threshold value, and a second roll restraining control part for carrying out a second roll restraining control in place of the ordinary control when the roll rate as sensed is equal to or greater than a predetermined threshold value. The second roll restraining control provides the damping-force characteristic of the shock absorber higher than that of the first roll restraining control.