Abstract:With the yield of essential oil from tropical water lily as an investigation index，the single factor test and orthogonal test were used to optimizing the supercritical CO2extraction process of essential oil from tropical water lily.Volatiles in essential oil were investigated by the gas chromatography-mass spectrometry method（GC-MS）.The optimization test result showed that the optimum supercritical CO2extraction conditions of essential oil from tropical water lily were as follow：extraction pressure was 27.5 MPa，extraction temperature was 45℃and cyclic extraction time was 120 min.The extraction rate of essential oil was 1.92%with the optimum process conditions.The analysis result showed that about 42 volatile compounds were identified in essential oil by the supercritical CO2extraction technology.There were 5 dominant components whose relative content in essential oil was above 5%.These components included that 6，9-heptadecadiene （the content was 25.406%），pentadecane（the content was 22.010%），benzyl alcohol（the content was 11.011%），8-heptadecene（the content was 9.916%）and farnesene（the content was 8.601%）.