To provide a vehicle drive system for appropriately maintaining four-wheel drive according to a driver's intention and road conditions, and improving running performance thereof.

The vehicle drive system includes a motor 5 which drives rear wheels 15R and 15L, and a 4WDCU 6 for controlling the electric energy inputted to the motor to control the motor drive. When a driver issues a request command for maintaining four-wheel drive or when the road condition of the vehicle changes, a control logic 200 of the 4WDCU 6 maintains a four-wheel drive mode in which the rear wheels are driven by the motor 5 and the front wheels are driven by an internal combustion engine 1.