Abstract:The present investigation aims to optimize the ultrasonic-assisted extraction process of total flavonoids from Rosa roxburghii leaves by surface response method.The effects of extraction time，solid-liquid ratio and solvent concentration on the extraction rate of total flavonoids from Rosa roxburghii leaves were studied by single factor experiments.On this basis，the relationship between the above factors and total flavonoids yield was determined by surface response method.The results showed that the optimum technological parameters for extracting total flavonoids were as follows：solid-liquid ratio 1 ∶36（g/mL），extraction time 34 min，and ethanol concentration 57%.The relative error between the predicted optimal yield of 41.36 mg/g and the actual yield of（40.87±0.09）mg/g was 1.18 %，which indicated a higher fitting degree between the predicted value and the actual value.