Abstract: Present invention relates to an apparatus to improve the riding feel of the vehicle when the rear wheels pass over a sporadic hollows or protrusions of a ground by altering the rear suspension characteristic, i.e. the spring constant and the damping force of the shock absorbers after such hollows or protrusions are detected by front wheels of the vehicle passing thereover and the detected hollow or protrusion is judged to exceed a predetermined size. Besides that, the present invention has another control measures to give a priority to the maintenance of the vehicle posture when the driving condition is that need drivability and stability more than the riding comfort over the above-mentioned rear suspension characteristic alteration.