OBJECTIVE： To estab lish the method for simultaneous determination of the contents of cyperotundone ， nootkatone，α-cyperone and aristolone in the volatile oil of Cyperus rotundus ，compare the content differences of 4 components in C. rotundus samples from different origins ，and to provide reference for germplasm screening ，development and utilization of the medicinal material. METHODS ：The volatile oil was extracted from 46 batches of C. rotundus from 12 origins. The contents of cypermenone，nootkatone，α-cyperone and aristolone in volatile oil were determined by HPLC. The determination was performed on Kromasil C 18 column with mobile phase consisted of methanol-water （68∶32，V/V）at the flow rate of 1.0 mL/min；the column temperature was 30 ℃；the detection wavelength was set at 242 nm；the sample size was 20 μL. Using the contents of above 4 components as evaluation indexes ，radar image analysis ，cluster thermal map analysis and principal component analysis were performed for comparing the quality of C. rotundus from different origins. RESULTS ：The results of content determination methodology investigation met relevant requirements ；the total contents of 4 components in volatile oil from C. rotundus from different origins ranged from 136.986 4 to 538.832 1 mg/g，of which the total content of samples from Yunnan was the highest （the average value was 476.059 2 mg/g）. Radar image analysis results showed that the whole contour in the 4 origins of Guangdong ， Jiangxi，Guangxi and Yunnan was large relatively and better balanced ，among which the samples from Yunnan had the largest overall contour and the best balance. The cluster thermal map analysis results showed that the samples from 12 origins could be grouped into 2 categories，the first category was from Hubei ，Jiangxi，Yunnan，Sichuan，Guangdong，Shandong，Henan and Shaanxi；the second category was from Guangxi ，Shanxi，Anhui and Hainan ；the quality of samples from the first category were better than that of samples from the second category. The principal component analysis results showed that the cumulative contribution rate of the first three principal components was 96.1％，and the samples from 12 origins were mainly clustered into two categories ，which was consistent with the results of cluster thermal map analysis. CONCLUSIONS ：Established HPLC method can be used for simultaneous determination of cypermenone ，nootkatone，α-cyperone and aristolone in volatile oil of C. rotundus from different origins. Among the samples from 12 origins，the quality of medicinal material from Yunnan is better.