The developmental processes of the protein body are studied on endosperm cells of Panax ginseng during seed maturation periods. The spherosome, mitochondria, rough endoplasmic reticulum, and ribosome are observed and then are gradually increased in early endosperm cells. Protein body developed from vesicles produced by the rough endoplasmic reticulum and was formed at the enlarged ends of rough endoplasmic reticulum. Also, vacuole-like protein body was observed in associated with rough endoplasmic reticulum. Golgi complex is observed in associated with vacuole and its vesicles containing proteinaceous granules moved and accumulated to the vacuole. Proteinaceous granules are deposited in the spherical or oval shaped vacuole and gradually, vacuole is surrounded by the multi-membranous structure. Rough endoplasmic reticulum, ribosome, Golgi complex, and vacuole are observed in associated with protein body formation.