It is provided a control device for a vehicle power transmission device including a shifting portion and an electric motor that provides regeneration via the shifting portion, the control device executing a downshift of the shifting portion if a traveling loss in the vehicle power transmission device after the shift is smaller than a traveling loss in the vehicle power transmission device at a current gear ratio during regenerative traveling, and the traveling loss in the vehicle power transmission device including at least one of a loss in the shifting portion and a loss in the electric motor, the loss in the shifting portion being calculated based on the operating oil temperature of the shifting portion and the loss in the electric motor being calculated based on the temperature of the electric motor.