Abstract:Objective: To extract polysaccharides from Dioscorea opposita by α-amylase and ultrasound.Method: The optimum condition of enzyme-assisted extraction has been obtained through orthogonal test according to the yield of polysaccharides.Result: A higher yield of polysaccharides was achieved at 55 ℃,pH 5.5,with a load of α-amylase 10 mg for 1.0 hour,the extraction rate was increased by in compare of sonolysis treatment alone.Conclusion:To carry out an enzyme treatment before ultrasound-assisted extraction elevated the yield of polysaccharides.