Abstract: Essential oil from the rhizome of Cyclorhiza waltonii was obtained by steam distillation. The chemical components of the oil were examined by means of capillary gas chromatography and gas chromatography-mass selective detector with HP-5 and Carbowax 20M stationary phases, Fifteen constituents of the oil were identified. The content of each component identified was determined by area normalization method. Of these, the content of ten compounds was higher than 2%. They are:α-pinene, sabinene, α-therpinene, p-cymene, β-phellandrene, γ-terpinene, terpinolene, terpineo-4-ol, cis-caryophyllene, duryl aldehyde and isoduryl aldehyde.The oil was found to compose of almost all the types of volatile composition,i, e., not only monoterpenes and sesquiterpenes but also alcohols0and aldehydes. Duryl aldehyde and isoduryl aldehyde are not common in volatile oils.