Abstract:The volatile constituents and content differences of peel oils from three types of grapefruit“Crystal pomelo”，“Lianjia pomelo”and“Shatian pomelo”in Jiangxi Nankang were studied to provide a reference for the improvement and identification of Nankang sweet pomelo varieties.Using the peels of three grapefruit varieties grown in the same habitat as materials，the essential oil was extracted by distillation，and the components of the essential oil were identified and analyzed using headspace gas chromatography-mass spectrometry （HS-GC-MS）.The experimental data were pre-processed，principal component analysis（PCA）analysis and orthogonal partial least squares-discriminant analysis（OPLS-DA）analysis，combined with SPSS 22.0 for t test and cluster analysis.The results showed that there were significant differences in the composition and content of the essential oils of the three grapefruit peels.A total of 49 substances were detected in three types of grapefruit peel essential oils，47 components were detected in Shatian pomelo peel essential oils，and crystal grapefruit and Lianjia pomelo had 46 components.The main types of compounds were terpenes（11 species），alcohols（13 species），esters（9 species），and aldehydes（5 species）.By t test（P<0.05）and OPLSDA analysis，it was found that there were 10 different components in Lianjia pomelo and Shatian pomelo，Crystal pomelo and Lianjia pomelo，and 8 different components in Crystal pomelo and Shatian pomelo.From the per－spective of PCA analysis and cluster analysis of grapefruit essential oil，Crystal grapefruit was divided into one category，Lianjia grapefruit was divided into one category，and Shatian grapefruit was divided into one category.