Abstract:Objective:Through chemical analysis of the essential oils obtained from prepared Chinese study Angelica to provide a scientific evidence for compatibility study of Siwu decoction. Method:Capillary GC-MS.Results:In the essential oils of the head of Angelica 88 peaks have been detected and 42 of them (51.34% of the oils)have been identified;while in those of the whole Anglica 94 peaks have been detected and 54 of them (90.86% of the oils)have been identified.Conclusion:Constituents in the essential oils obtained from prepared Chinese Angelica have been identified for the first time.