A suspension control system for feedback-controlling the sprung mass acceleration signal y.sub.m and a method for introducing the unsprung mass acceleration signal y.sub.L into a tuning circuit to tune gain of an FIR filter. In this system, tuning is performed so as to cancel the road surface input y.sub.m close to a reference frequency (around 10-12 Hz). As a result, the sprung mass acts as a dynamic damper upon the road surface input y.sub.m close to the reference frequency (around 10-12 Hz), however, frequency bands other than the reference frequency band do not receive the contribution of the second term in the equation (6). That is, output from the tuning circuit to an adder becomes almost zero, and normal sky-hook control is performed. Though the sprung mass system acts as a dynamic damper, the unsprung mass system exceeds the sprung mass system in mass, and excessive resonance does not occur.