Abstract:In order to optimize the extraction method of total flavonoids from Agrimonia pilosa Ledeb.，based on single factor experiments，extraction time，extraction temperature，ethanol concentration and ratio of solid to liquid were selected as influencing factors and the yield of total flavonoids as response during extraction.The experiment method was designed according to central composite design and each variable and their interactions effects on the yield of total flavonoids were studied.The quadratic multinomial model on the yield of total flavonoids and each factor was established by using the Design-Expert software.The results showed that the regression model was very significant and the forecast was strong.Ethanol concentration and extraction temperature were the main factors.The results showed that the optimum extraction conditions were as follows：extraction time of 100 min，extraction temperature of 100℃，ethanol concentration of 30%and ratio of solid to liquid 1∶15（g/mL）.The verification experiment，repeated three times in the best extraction conditions，showed that the average yield of flavonoids was 9.92%.