Abstract: In order to improve the comprehensive utilization rate of peony（Paeonia suffruticosa Fengdan） leaf of Fengdan resources, the polyphenols in the leaves of peony were extracted by cellulase method, and the polyphenols were used as the index. The effects of cellulase concentration, enzymatic hydrolysis temperature, enzymatic hydrolysis time and pH value on the extraction of polyphenols in peony leaves were investigated by response surface. The results showed that the best condition for extraction of polyphenols from peony leaves by cellulase waswhen the concentration of cellulase was 150 U/mL, the pH was 5.0, the enzymatic time was 105 min, the temperature of enzymatic hydrolysis was 50 ℃. Under this condition, the theoretical prediction value of polyphenol content was 34.66 mg/g. The antioxidant activity of the best condition for extraction was examined. The DPPH· scavenging abilities of Fengdan leaf extract reached 82.15% when the extract concentration was 0.06 mg/mL; the hydroxyl scavenging abilities reached 27.10% when the concentration was 0.32 mg/mL;reducing abilities of the potassium ferricyanide absorbance was 3.41, when the concentration of the extract was 10 mg/mL.

Key words: Fengdan peony（Paeonia suffruticosa Fengdan）, polyphenols, enzyme extraction, design of response surface, dntioxidant activity