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In this paper, the optimization of the suspension was performed by using the criterion taking account of human sensitivity in order to improve the riding comfort. For the purpose of decreasing the vibration at an uncomfortable frequency range for human beings, the frequency-shaped criterion was formulated. An active suspension with feedback and feedforward controls was designed by using the optimal control theory from the criterion. The suspension model is assumed to be a two-degree-of freedom system, and the acceleration of road unevenness is taken to be colored noise. From numerical calculations and experiments, it was made clear that optimal control with a feedback link alone obtained from the frequency-shaped criterion function can reduce the acceleration of a vehicle at the desired frequency range. Furthermore, it was clarified that the control with a feedforward link is more useful than the one with a feedback link alone in the same control force.