essential oil from the epigeal portion of artemisia scoparia waldst. et kit. collected in different regions of buryatia and mongolia has been isolated using steam distillation. the yield of essential oil from the stems and leaves of a. scoparia collected in different regions of buryatia and in the selenga aymag of mongolia ranged from 0.06 to 0.40%, that is, the variation was rather high. the composition of the oil was analyzed using chromatography with mass spectrometric detection on a gas chromatography device agilent packard hp 6890 n with a quadrupole mass spectrometric detector hp msd 5973. the total number of compounds detected exceeded 100. the major components of artemisia scoparia oil were the following: p -cymene (0.6-15.2%), limonene (0.1-6.3%), -pinene (0.2-10.1%), -pinene (0.4-8.9%), trans --ocimene (0.3-5.4%), caryophyllene (4.6-13.8%), germacrene d (11.5-40.3%), spathulenol (4.0-11.7%), and caryophyllene oxide (4.3-15.6%). several chemotypes of essential oil from a. scoparia were identified according to the nature of the major components: 1) oil that contained acetylene hydrocarbons (from plants collected in gilan, mazandaran, kashan, and tigran provinces of iran, tajikistan, and the european part of the cis); 2) oil that contained monoterpenes and aromatic compounds (from plants collected in the khorasan province of iran, india, and south korea); and 3) oil that contained monoterpenes or aromatic and sesquiterpene compounds (from plants collected in kazakhstan and mongolia). the major components of a. scoparia essential oil obtained from buryatian plants belonged to the classes of mono- and sesquiterpene compounds, and thus the oil can be assigned to the third chemotype characteristic of a. scoparia from geographically close regions.