This study was carried out to investigate the localization of lipids and lipase activity with lipid staining and cytochemical technique in endosperm cells of Panax ginseng C.A. Meyer seed. In endosperm cells of indehiscent seed, protein bodies facing the umbiliform layer are different in electron density during the various degraded processes. Gradually, protein matrix near the cell wall was lysed and electron lucent inclusions appeared on umbiliform layer. The protein body with high electron density and the spherosome with low electron density were observed in endosperm cells. As a result of lipid staining, electron density of spherosome is more intense than those of the protein matrix within the protein body in endosperm cells of indehiscent seed. Free spherical spherosomes within the umbiliform layer have a high electron density. The spherical spherosomes were more electron densed and were uniform in comparison with the cytoplasmic proteinaceous granules in endosperm cells of seed with red seed coat. The major component of spherosome was determined to be lipid. Lipase activity occurs in the spherosome and near the endosperm cell wall facing the umbiliform layer. Cytochemical reaction products of lipase were observed in the spherosome membrane and in the inner regions of spherosome. After protein bodies were digested, lipase activities were observed in free spherosomes and near the cell wall of endosperm cells. Umbiliform layer composing of fibrillized wall and digested materials of the endosperm cell showed a little lipase reaction products.