Cephalotaxus koreana Nakai is endemic species of Korea. Since old days, the fruits have been used as a parasiticide and leaves have been used for a pierced wound by insects. The essential oil components from its aerial parts and stem bark by steam distillation were investigated. Several compounds were characterized by GC-Mass spectra. It was found that the leaves, stembark and flowers contain the compounds of essential oils, 1-octene-3-ol, hexadecanoic acid; $alpha$-pinene, $Delta^3$-carene mainly, linalylacetate, $eta$-cubebene, 3,4-octadine-7-methyl , ferruginol(stem bark) and $alpha$-pinene mainly, $eta$-pinene , cyclopropane-1,1-dimethyl-2-(3-methyl-1,3-butadienyl), etc. This Cephalotaxus spp. contains the first components of ferruginol(M.W.286.03, $C_{20}H_{30}O)$ which belong to diterpene.