A new control algorithm of active suspension is proposed for rough roads. In this study, a quarter car model is used. The large tyre deflection and the stroke limit of the actuator are taken into consideration. A virtual damper concept is proposed to attenuate the tyre deflection by feeding back the relative velocity between road and unsprung mass to the force actuator. A fuzzy preview control scheme is presented to generate a reference curve by sensing the road information ahead of the vehicle so that the actuator can operate within the stroke limit even in the rough road. Computer simulations are performed to verify the above concepts, and it is shown that satisfactory performance can be achieved by the proposed control scheme.