Because of steep rise of international energy cost in recent years, high efficiency has been emphasized in energy policy. As far as injection molding machine is concerned, hybrid method using hydraulic and electric systems became the key to this energy saving. The energy saving and molding reproducibility of hybrid injection molding process were shown experimentally. The power consumption of hybrid injection molding machine is reduced to 38% as compared with that of hydraulic machine. Furthermore, the molding reproducibility was shown for both methods.