A control system for a vehicular drive unit including an engine 1, a motor/generator 2, a transmission 4, and a planetary gear 30 connected to the engine through a starting clutch 31 and to the motor/generator and the transmission. The control system includes a motor drive control acting as a program in an ECU 70 for driving the motor/generator in a predetermined direction prior to the application of the starting clutch at a split starting time of a vehicle, when the starting clutch is applied to interlock the engine and the motor/generator through the planetary gear to output a reaction of an engine output torque to the motor/generator.