A target drive shaft torque is calculated from an accelerator pedal opening degree and a vehicle speed. During acceleration of the vehicle wherein target device shaft torque is not negative, a target engine torque for generating target drive shaft torque is calculated, and a target throttle opening degree for providing target engine torque is determined. On the other hand, during deceleration of the vehicle wherein target drive shaft torque is negative, a target throttle opening degree is determined from accelerator pedal opening degree at which the drive shaft torque is zero and the throttle opening degree at which the engine torque is zero. This target throttle opening degree is in a proportional relation to the accelerator pedal opening degree and thus when accelerator pedal opening degree target throttle opening degree.