A plant control system using response specifying control that makes it possible to independently set a follow-up behavior for an output value of a plant when a target output value of the plant changes and a convergent behavior for a difference between a target output value and an output value when the output value of the plant changes. The control system has a controller for determining a clutch stroke on the basis of a model equation of a clutch device such that a target rotational speed and an actual rotational speed of the clutch device coincide with each other. The controller includes a target value filter for carrying out filtering computation on a target rotational speed to calculate a filtering target value that converges to the target rotational speed with a response delay, and a response specifying control unit that determines the clutch stroke by response specifying control such that the filtering target value and the clutch rotational speed coincide with each other.