To improve the fuel consumption in a device for controlling driving force by setting an optimal compression ratio corresponding to the traveling state of a vehicle.

The device for controlling driving force is provided with: an engine 11 capable of rotary driving by transmitting the driving force to a driving wheel 19 of the vehicle; a variable compression ratio mechanism 20 having a driving device capable of changing the compression ratio of the engine 11; and an ECU 21 that can change the compression ratio according to the operating condition of the vehicle and decides the variability and fixing of the compression ratio in consideration of the driving energy of the driving device when the vehicle runs repeating the acceleration and coasting.