Objective: To optimize extraction technology of polysaccharide from roots of Arctium lappa. Method: Polysaccharide was extracted by water extraction and alcohol precipitation method with yield of polysaccharide as index;Response surface methodology was used to study on influencing factors of determination of polysaccharide from roots of A. lappa

response surface and contour were made with extract ratio of polysaccharide as response value. Result: Optimum extraction technology conditions were solid-liquid ratio of 1 : 14.43

extraction temperature 84.85 ℃

extracting time 3.81 h.Under these conditions

yield of polysaccharide from roots of A. lappa was 6.16%. Conclusion: This optimized technology was stable and feasible.