Abstract: Objective:The extraction process and its properties of polysaccharide from the branches and leaves of Chrysanthemum indicum were studied,which would provide comprehensive utilization basis for this natural resource. Method:The polysaccharide was extracted from the branches and leaves of Chrysanthemum indicum with ultrasonic assistant extraction in hot water,after its powders decolorized and degreased,the polysaccharide concentration was determined by phenol-sulfuric acid method. The extraction concentration of the polysaccharide was taken as evaluation standard,investigated the effects of single factor as follows:Ratio of solid to liquid,ultrasonic temperature,ultrasonic time,ultrasonic power etc.,then optimized and designed through orthogonal experiments,its monosaccharide composition were analyzed by GC-MS and its antioxidant activities were tested by Fenton system. Results:The optimum extraction process was as follows:Ratio of solid to liquid at 1:40 (g/mL),ultrasonic temperature of 80℃,ultrasonic time of 35 min,ultrasonic power of 360 W,the best extraction concentration of polysaccharide reached 6.26 g/100 g. The polysaccharide was a heteropolysaccharide composed of galactose,glucose,arabinose,rhamnose,mannose and xylose which according to the chromatographic peak area ratio 34.58:27.61:19.32:10.53:4.11:3.85,had antioxidant activities. Conclusion:The polysaccharide from the branches and leaves of Chrysanthemum indicum was extracted with ultrasonic assistant extraction in hot water had antioxidant activity.