Abstract: Gaoben (Ligusticum) is a well-known drug used in Chinese traditional medicine. Chemical constituents of essential oil from four species of Gaoben were compared by GC-MS/DS combination on SE-54 capillary column (0.25 mm×30 m). One hundred and eleven components were identified. It was found that all oils contained myristicin, cnidilide, alpha-pinene and terpinolene. Conioselium tataricum Hoffm. contained beta-phellandrene, ligustilide, butylidenephthalide and enemicin. Twenty-four components were identified in Ligusticum jeholense Nakai, et Kitag. The total content of which in the essential oil was found to be 92.9%. Among them the major constituents are beta-phellandrene (33.32%), 4-terpinyl acetate(13.82%) and ligustilide(6.23%).25 components were identified in Ligusticum sinense Oliv., with a total content of 91.8% in the essential oil. The major constituents are limonene (14.44%), neocnidilide (25.57%) and cnidilide (10.78%). 25 components were identified in the Conioselium tatarieum Hoffm. which is indigenous to Nileker. The total content of these components in the oil is 98.26%. It contains mainly myristiein (44.25%), beta-phellandrene (18.72%)and enemicin (11.08%). 37 components were identified in Conioselium tatarieum Hoffm. Which is indigenous to Chabuchaer, the major constituents of the essential oil are beta-phellandrene (25.40%), cnidilide (14.57%) and ligustilide(10.95%). The total content of these 37 compounds is 87.1%.