A suspension control system allows a state variable of a vehicle used for the damper damping force control to be computed at a high precision without regards to the caster angle given to the suspension geometry. A suspension control system for a vehicle provided with a variable damper that can adjust a damping force according to an input signal comprises a wheel rotational speed sensor for detecting a wheel rotational speed, a gain circuit for computing the unsprung load of each wheel according to the wheel rotational speed variation detected by the wheel speed sensor, a single wheel model computing unit for computing the sprung velocity and the stroke speed by inputting the unsprung load to a single wheel model representing the behavior of the vehicle, and a damper control unit for controlling a damping force of the variable damper according to the computed sprung velocity and stroke speed.