The essential oil of Korean ginger(Zingiber officinale Roscoe) was isolated by liquid carbon dioxide extraction method and fractionated into one hydrocarbon fraction and two oxygenated hydrocarbon fractions by using silica gel column chromatography. The compositions of the resulting oils were investigated by GC and GC-MS spectrometry. Out of 102 identified compounds, 44 were identified by comparing GC retention time and mass spectral data with authentic samples and 58 were tentatively identified according to mass spectral data only. The major compounds of hydrocarhon fraction were zingiberene, β-sesquiphellandrene, γ-bisabolene, γ-cardinene, ar-curcumene, and those of oxygenated hydrocarbon fractions wee geranal, sesquisabinene hydrate, borneol and zingiberenol. The major compounds of ginger oil were zingiberene, citronellol＋β-sesquiphellandrene, geranial, γ-bisabolene and ar-curcumene＋geranyl acetate, and ginger oil contained higher amounts of sesquiterpene hydrocarbons. The yield of extract was 6.96%.