A control device for a hybrid vehicle having an internal combustion engine as a power source, a motor/generator as a power source, a first clutch interposed between the internal combustion engine and the motor/generator and capable of changing a transfer torque capacity continuously or stepwise, and a second clutch interposed between the motor/generator and the drive wheel and capable of changing a transfer torque capacity continuously or stepwise, so as to select a drive mode between an electric vehicle mode in which a vehicle is driven only using power from the motor/generator by releasing the first clutch and engaging the second clutch and a hybrid electric vehicle mode in which a vehicle is driven using power from both the internal combustion engine and the motor/generator by engaging both the first and second clutches (6 and 7), the control device comprising: a first-clutch engagement control means configured to engage the first clutch when a mode switches to the hybrid electric vehicle mode from the electric vehicle mode; and a second-clutch engagement control means configured to slip-engage the second clutch when the internal combustion engine starts using the first-clutch engagement control means, characterized in that the control device further comprises a motor/generator control means configured to increase a torque of the motor/generator exerting to reduce a slippage of the second clutch as a deceleration request occurs due to a decrease in an accelerator pedal opening while the second clutch is controlled to start the internal combustion engine for switching from the electric vehicle mode to the hybrid electric vehicle mode, compared to a case where the accelerator pedal opening does not decrease during the slip engagement, and the control device is configured such that even when the accelerator pedal opening is decreased after the start control for the internal combustion engine is initiated, the internal combustion engine stops after the completion of the start control to start the internal combustion engine. a first-clutch engagement control means configured to engage the first clutch when a mode switches to the hybrid electric vehicle mode from the electric vehicle mode; and a second-clutch engagement control means configured to slip-engage the second clutch when the internal combustion engine starts using the first-clutch engagement control means, characterized in that the control device further comprises a motor/generator control means configured to increase a torque of the motor/generator exerting to reduce a slippage of the second clutch as a deceleration request occurs due to a decrease in an accelerator pedal opening while the second clutch is controlled to start the internal combustion engine for switching from the electric vehicle mode to the hybrid electric vehicle mode, compared to a case where the accelerator pedal opening does not decrease during the slip engagement, and the control device is configured such that even when the accelerator pedal opening is decreased after the start control for the internal combustion engine is initiated, the internal combustion engine stops after the completion of the start control to start the internal combustion engine.