A control system for a drive unit of a vehicle, including a reaction force establishing device controlling a speed change ratio of a continuously variable transmission, and a clutch mechanism arranged on a power transmission route from the continuously variable transmission to a wheel and in which a torque capacity thereof is controllable. A first input torque control mechanism lowers a torque to be inputted to the clutch mechanism through the continuously variable transmission, by controlling a torque of the reaction force establishing device while the torque capacity of the clutch mechanism is being controlled. The system reduces a change in a torque inputted to a clutch mechanism, in case of carrying out a speed change operation of a continuously variable transmission and engaging the clutch mechanism.