Objective To optimize the extraction of polysaccharide from Rhizoma Paridis in Shaan'xi by ultrasonic method.Methods Response surface method was employed to determine the optimal technologycondition.Results The optimal extraction conditions were as follows: extraction temperature 72 ℃,ultrasonic power 330 W,extraction time 25 min and ratio of water to raw material 14 :1(mL :g).The yield of polysaccharide was 3.87% with the above mentioned conditions.Conclusion This method is suitable for the ultrasonic extr...