Abstract: The volatile components in angelica sinensis oil from Minxian were analyzed for the first time by gas chromatography- quadrupole mass spectrometry ( GC- Q MS) and gas chromatography- ion trap mass spectrometry (GC-IT MS) . Total of thirty compounds were identified by MassworksTMsoftware analysis, MS/MS qualitative analysis approach of GC-IT MS and library search. The major volatile components of essential oil from angelica sinensis were Z- ligustilide, E- ligustilide, β- Ocimene, α- Pinene, 3- Butylidene phthalide andγ-Elemene. Results showed that the results obtained by three kinds of qualitative methods which were MassworksTMsoftware analysis, MS/MS qualitative analysis approach of GC-IT MS and library search mutual authentication could improve the accuracy and reliability of identification of unknown composition.