A drive system control method and a drive power transmission control system for a four-wheel drive vehicle are provided for enabling the vehicle to operate selectively in an ordinary mode and an anti-vibration mode. In the ordinary mode, the connection force of a coupling device which is provided between front and rear wheel torque transmission axles is kept relatively high, and the front and rear wheel torque transmission axles are brought to connect prime drive wheels with secondary drive wheels, so that four-wheel drive traveling of the vehicle can be realized. The operation mode of the vehicle is switched from the ordinary mode to the anti-vibration mode where the secondary drive wheels slip when the vehicle begins to start in the ordinary mode. In the anti-vibration mode, the connection force of the coupling device is relatively weakened to substantially separate the front and rear wheel torque transmission axles from each other. Thus, the resilient force produced by the torsion of the front and rear wheel torque transmission axles which is caused by the slip of the prime drive wheels or the secondary drive wheels is released between the front and rear wheel torque transmission axles, so that the vibration which would otherwise be generated when the vehicle performs the four-wheel drive starting can be suppressed compared with that in the prior art.