Abstract: In this study,the effect of extraction solvents,liquid solid ratio，ultrasonic power，ultrasonic time，and ultrasonic temperature on the yield of Lycium ruthenicum Murr fruit oil was studied.On the basis of single factor tests，the mathematical regression model was established about the response values (extraction yield of Lycium ruthenicum Murr fruit oil) and independent variables ( liquid solid ratio，ultrasonic time and ultrasonic temperature) through BoxBenhnken center composite design (three factors and three levels) and response surface analysis.The result by response surface methodology indicated that effective factor on oil yield was the order as follows:ultrasonic temperature>liquid solid ratio>ultrasonic time.The optimum factors were:liquid solid ratio 12 mL/g,ultrasonic temperature 51 ℃ and ultrasonic time 37 min．The extraction yield of Lycium ruthenicum Murr fruit oil was 7.19%.The results of HPLC fluorescence detection analysis showed that the main components of Lycium ruthenicum Murr fruit oil were unsaturated fatty acids,the content of which was 64.86%.The main unsaturated fatty acids were oleic and linoleic acids,and the percentages of them were 38.73% and 18.75%,respectively.The main saturated fatty acids were stearic and palmitic acids,and the percentages of them were 10.80% and 11.16%,respectively.

Key words: response surface methodology, ultrasonicassisted extraction, Lycium ruthenicum Murr, fatty acids, component analysis