Abstract: In this paper, the chemical constituents of the volatile iols of three species of Rabdosias from tibet: Ⅰ. Rabdosia Parrifolia (Boital) Haara: Ⅱ . Rabdosia pseudo-irrorata C. y. Wu. ; Ⅲ. Rabdosia rugosa (Wall. )hara have been alalyzed by GC/MS. From Ⅰ , 84 peaks were separated, of which 27 major components were identified, constituting 60% of the total peak area. From Ⅱ , 72 peaks were separated, of which 39 major components were identified, consituting 82.5% of the total peak area. From Ⅱ , 90 peaks were separated, of which 39 major components were identified, constituting 62.1 % of the total peak area. The constituents and ralative quantity of the three oils were compared.

Key words: Kabdosia parrifolia (batal) Hara, Rabdosia pseudoirrorata C. Y. Wu., Kabdosia rugosa (Wall. )hara, volatile oil, GC/MS