PURPOSE: To keep the vehicle speed time-change rate constant during an acceleration operation and improve operability by controlling the fuel feed quantity to an internal combustion engine to make the vehicle speed time-change rate constant when the vehicle speed time-change rate is not constant during the acceleration operation of the internal combustion engine.

CONSTITUTION: Detecting means such as a vehicle speed sensor 14, an engine rotating speed sensor 16 and a throttle sensor 18 are connected to a control means 12 connected to a fuel discharge section 10. The signal from the throttle sensor 18 is inputted to the control means 12 during the acceleration operation of an internal combustion engine 4, the signal from the vehicle speed sensor 14 is inputted to an acceleration arithmetic section 20, if the vehicle speed time-change rate is not constant due to the fuel with a different nature used as the specific fuel, the fuel discharge section 10 is controlled to increase the fuel quantity to the internal combustion engine 4 then that when the normal acceleration augmentation is corrected so that the vehicle speed time-change rate is made constant. The vehicle speed time-change rate can be kept constant, and drivability can be improved.