Abstract:The Extraction process parameters and antioxidant activity of crude polysaccharides from Chuanmingshen violaceum polysaccharides（CVP）in reservoir area were studied by ultrasound-assisted enzymatic extraction.The effects of enzyme dosage，extraction temperature，and extraction time and extraction pH on the extraction rate of polysaccharides were investigated by single factor experiments，and the range of technological parameters was determined.In this basis，the extraction conditions of polysaccharides were optimized by response surface methodology.The results showed that the extraction rate of CVP was the highest with the predict－ed value of 49.98% under the conditions of 0.26 g enzyme dosage，54℃extraction time of 43 min and pH value of 4.20.According to this condition，the extraction rate was（49.52±0.53）%，which was close to the theoretical predicted value.Fourier transform infrared spectroscopy（FT-IR）analysis showed that pyranose residues may exist in CVP structure.Antioxidant experiments showed that CVP had good antioxidant activity in vitro，and was a potential natural antioxidant component.