Abstract:The oil of vetiveria was extracted by ultrasonic assisted organic solvent extraction，and the yeild of vetiver oil after silica gel was used as an index.Based on the single factor experiment，the response surface method Box－Behnken experiment design was carried out，and the order of the factors affecting the yield of the vetiver oil was the ratio of material to liquid＞ultrasonic temperature＞ultrasonic time and the interaction between the ratio of material to liquid and ultrasonic temperature is more significant.When the ethanol was used astheextractionsolvent，theparticlesizewas80mesh －100mesh，theratioofmaterialtoliquidwas1 ∶12（g/mL），the ultrasonic time was 35 min，the ultrasonic temperature was 68℃.Under this condition，the yield of the vetiver oil was 3.21%.The chemical composition of the essential oil was analyzed by GS－MC.A total of 22 compounds which accounted for 76.96%of the total extract were identified.