Abstract: Essential oil of pomelo leaf and flower was extracted by supercritical CO2 fluid extraction technology.Their compositions and relative contents were quantitatively determined by GC-MS with peak area normalization method.Results showed that sixty-one chromatogram peaks from essential oil of pomelo leaf were isolated,thirty-nine volatile compounds had been identified,which was accounted for 90.05% of total volatile compounds.The predominant volatile components were isospathulenol(21.36%),caryophyllene oxide(17.16%),β-caryophyllene(8.40%),α-copaene(2.07%),isoaromadendrene epoxide(2.01%).Forty-two chromatogram peaks from essential oil of pomelo flower were isolated,twenty-eight volatile compounds had been identified,which was accounted for 89.31% of total volatile compounds.The predominant volatile components were farnesol(19.02%),nerolidol(18.24%),borneol(6.60%),linalool(4.03%),nerol(2.57%).Twelve chemical components such as nerol,geraniol,geraniol acid,β-aryophyllene were both presented in pomelo leaf and flower,but with different contents.