Hyaluronic acid was extracted from crude chicken comb by ethanol method and then purified by CTAB method.The degree of degradation was based on the reduced sugars content after hyaluronic acid degradation.Single factor experiment and response surface method analysis established two regression models to optimize the combination of the four factors of liquid material ratio,pH,degradation time,hydrogen peroxide concentration,The result of response surface experiment showed that the best condition was: ratio of material to liquid( H 2 O 2 ∶Vc) 4.13∶1,pH 8, the degradation time 5 min,and H 2 O 2 concentration 1.67 mol/L.The molecular weight of hyaluronic acid was 22671.88 after extraction and purification,molecular weight hyaluronic acid was 1764.67 under the above conditons.