Essential oil of the root of Angelica gigas Nakai (Umbelliferae) was investigated. Essential oil was obtained from the dried roots by steam distillation and fractionated by column chromatography. Each isolate or fraction was identified by GC, GC-MS and spectral analysis. It was found to contain eleven monoterpenes such as ${alpha}-pinene,;camphene,;{eta}-pinene,;myrcene,;{alpha}-phellandrene,;{Delta}-3-carene,;{alpha}-terpinene,;p-symene,;limonene,;{gamma}-terpinene$ and terpinolene and also found to contain 4-vinylguauacol, myristicin, elemol, ${eta}-eudesmol,;{alpha}-eudesmol,;four;sesquiterpenes;involving;{Delta}-elemene$. Four sesquiterpenes and five sesquiterpene alcohols were tentatively identified by comparison of their mass spectra.