OBJECTIVE:To compare the volatile components extracted from the roots,stems and leaves of Gaultheria yunnanensis. METHODS:Steam distillation method was used to extract the volatile oils from roots,stems and leaves of G.yunnanensis. Chem. constituents were analyzed by GC-MS. NIST 2011 standard mass spectral library was adopted to select the chromatog. peak with a matching degree higher than 80,and combined with relevant literatures for identification. Relative percentages of chem. constituents were calculated by peak area normalization. RESULTS:Totally 95 chromatog. peaks were detected in valatile oil from the roots of G. yunnanensis and 54 chem. constituents were identified,accounting for 82.35%of the total content of root volatile components. The constituents with relatively high content were Me salicylate(20.30%),n-hexadecanoic acid(19.86%),(Z,Z)-9,12-octadecadienoic acid(9.26%),phenanthrene(4.37%) and so on. Totally 69 chromatog. peaks were detected in volatile oil from the stems and leaves of G. yunnanensis and 46 chem. constituents were identified,accounting for 97.10% of the total content of volatile components in stems and leaves. The constituents with relatively high content were Me salicylate(86.72%),n-hexadecanoic acid(2.60%),(Z,Z,Z)-9,12,15-octadecatrienoic acid(1.25%)and so on. Both of them contained 16 common constituents such as alkenes esters,acids and so on. CONCLUSIONS:The chem. constituents of volatile oils extracted from the roots,stems and leaves of G. yunnanensis are mainly esters and acids. The components are similar to each other, but the contents of acids in the roots and esters in the leaves and stems are higher.