Abstract:Essential oils can be obtained from branches and leaves of Mur-raya tetramera growing in Yimen, Tonghai and Jianshui of Yunnan proyince by respectively steam distillation. By GC--MS, altogether 27 chemical constitu- ents were isolated and identified. In these chemical constitucnts, 21 constituents were isolated and identified from the essential oil of Murraya tetramera gro- wing in Yimen, their content accounted for 99.69% of the esscntial oil, 18 constituents were isolated and identified from the essentiai oil of Murraya tetramera growing in Tonghai, their contcnt accounted for 99.44% of the cssen- tial oil ; 20 constituents were isolated and identified from the essentiel oil of Murraya tetramera growing in Jianshui, their content accounted for 99.72% of the essential oil. In these constituents, except that caryophllene was sesqui- terpenescne, other 26 constituents were all monoterpenes or their oxygenous derivatives.