Objective: Agastache rugosa polysaccharide was extracted from the branches and leaves of A. rugosa

the research can provide and supply scientific basis for the search of its polysaccharide antioxidant activity to empolder A. rugosa medicinal materials. Method: The polysaccharide was obtained from A. rugosa branches and leaves by ultrasonic extraction method

and tested L9(34) orthogonal experiment on the base of material-liquid ratio

ultrasonic time and pH value

to optimize A. rugosa polysaccharide extract technology;A. rugosa polysaccharide to remove hydroxyl radical was also studied. Result: The best A. rugosa polysaccharide extracting technology assisted by ultrasonic was material-liquid ratio 1:10

ultrasonic time 30 min

and pH value 6

and the extraction rate of polysaccharide was reached up to 7.50%. A. rugosa polysaccharide had significant scavenging effect for hydroxyl radical produced by Fenton reaction theory. Conclusion: A. rugosa polysaccharide had antioxidant activity. The polysaccharide may be extracted from the branches and leaves of A. rugosa

and had development value.