Abstract:The ethanol concentration, solid-liquid ratio, ultrasonic time and temperature were optimized by response surface-satisfaction function with extraction rate of polysaccharide and flavonoid from Curcuma Longa as response values. The results showed that the optimum extraction conditions of C. Longa polysaccharide and flavonoids were as follows: water as extraction solvent, ultrasonic temperature 50 ℃, material-liquid ratio 1∶22 (g/mL), ultrasound time 20 min. The extraction rate of polysaccharide and flavones were 1.01% and 0.23% respectively, and the satisfactory degree is 0.823 7. The difference between the predicted value was very small, which showed that the extraction process was reliable and feasible. The antioxidant activity test showed that the maximum scavenging efficiency of polysaccharide and flavones to DPPH free radical was (42.91±0.54)% and (65.46±0.38)% respectively, and the maximum free radical scavenging rate to ABTS was (33.28±0.69)% and (34.26±0.18)%, respectively. This indicated that they had obvious scavenging ability to these two kinds of free radicals, and the flavonoids were stronger than the polysaccharides.