Abstract:The essential oil of the "Lang-Du Dang-Gui" (Angelica sp.) from the Lang-Du Mountain (Yunnan Province) has been analysed qualitatively and quantitatively by means of capillary GC/MS/DS on the Finnigan-4510, and forty-two constituents, which made up 96.83 of the total oil, have been identified. Ligustilide (73.98) and cis-P-ocimene (12.18) were the principal components of the essential oil. In addition, four known compounds that are lignoceric acid (1 ), P-sitosteroK 2 ), umbelli-ferone(3), and sucrose (4) have been isolated from the non-volatile part of the same sample.