An assisting ejection device is provided for assisting ejection a hatch of a hatchback. The assisting ejection device includes spring-biased rod to act on the hatch. The spring is in a compressed condition when the hatch is closed so that when the hatch is released from the closed condition, the spring that is allowed to extend provides a springing force to help pneumatic cylinders that are originally provided to automatically lift the hatch to eject the hatch toward a flip-up position. The springing force effectively reduces the load applied to the pneumatic cylinders in opening the hatch so as to extend the service life of the pneumatic cylinders.