Abstract:This research used Aastragalus as an experimental material，ultrasonic extraction was used to improve extraction technology of Astragalus polysaccharides.Astragalus polysaccharides extraction rate as evaluation index，and some single factor experiment were studied，such as ultrasonic temperature，ultrasonic time，liquid-solid ratio and ultrasonic power on the effect of Astragalus polysaccharidess extraction rate.On basis of which center-united experimental design and response surface methodology were applied to optimize the extraction condition of Astragalus polysaccharides.Results showed that the optimal extraction parameters was ultrasonic time 87 min，liquid-solid ratio 22 ∶1（mL/g）and ultrasonic power 600 W.Under this condition，the extraction rate of polysaccharides was 6.07%.