PURPOSE: To improve the control responsibility and the stability of the behavior of a vehicle by temporarily making an electromagnetic clutch as a clutch used for controlling the front and rear wheel drive force distribution of a four wheel drive vehicle keep in a neutral state of ON and OFF in ON and OFF switching.

CONSTITUTION: In a four wheel drive vehicle, exciting current of the solenoid 5a of a electromagnetic clutch 5 for controlling front and rear drive force distribution is controlled by a controller 6 based on wheel revolution VFL, VFR, VRL, and VRR sent from wheel revolution sensors 15 to 18, and when a clutch is turned ON from OFF, the exciting current is kept in the neutral state of ON and OFF by switching a clutch OFF current map to a clutch ON current map.