A control system for a limited-slip differential gear unit is cooperative with a traction control system to provide better vehicle driving stability. The control system for a limited-slip differential gear unit is capable of optimizing driving torque transmission characteristics for improving cornering stability of the vehicle. The limited-slip differential gear unit control system, according to the invention, is operative in response to difference of wheel slippages at driven wheels for slip limiting force in order to adjust wheel slippage of heavier load driven wheel at a predetermined value. The control system is cooperative with a traction control system which is detective of wheel slippage due to wheel spinning caused by excessive driving torque to be applied to the driven wheels and adjusting the driving torque to be distributed to the driven wheels.