OBJECTIVE：To esta blish a method for determining the contents of lupenone and stigmasterol in the rhizome ，stem and leaf of Mosa basjoo from the same plant ，and to provide reference for the substitute resource for the effective components of M. basjoo . METHODS ：UPLC method was adopted. The determination was performed on Zorbax Rrhd Eclipse Plus C 18 column （100 mm×2.1 mm，1.8 μm）with mobile phase consisted of acetonitrile-methanol （78.5∶21.5，V/V）. The detection wavelength was set at 210 nm；the flow rate was 0.15 mL/min；the column temperature was 30 ℃ and the sample size was 1 μL. The results of content determination of lupinone and stigmasterol in the rhizome ，stem and leaf of 9 batches of M. basjoo from the same plant were analyzed by the methods of comparative analysis between groups ，principal component analysis and cluster analysis. RESULTS：The mass concentration of lupenone and stigmasterol had a good linear relationship with the corresponding peak area within the range of 11.16-357.10 and 8.83-160.40 g/mL（R2 were 0.999 2 and 0.999 1，respectively）. RSDs of precision ， repeatability and stability tests were all less than 3％. The average recovery rates of lupenone and stigmasterol were 101.44％ and 98.32％，and the RSDs were 1.77％ and 1.81％（n＝6），respectively. The average contents of lupenone and stigmasterol in stems of M. Basjoo were significantly higher than those of rhizome and leaves of M. basjoo （P＜0.05）. There was no statistical significance in the contents of lupenone and stigmasterol between stem and leaf of M. basjoo from same plant （P＞0.05）. Results of principal component analysis showed that the contents of lupanone and stigmasterol were different in rhizome ，stem and leaf of M. basjoo from the same plant. Rhizome ，stem and leaf of M. basjoo were divided into three types through cluster analysis ，among which the rhizome had significant difference with the other two parts. CONCLUSIONS ：The method is simple ，rapid，specific， reproducible and accurate. It can be used for the content determination of lupenone and stigmasterol in different parts of M. basjoo . The stem of M. basjoo can replace the rhizome of M. basjoo as the source of lupinone and stigmasterol.