Abstract: In this paper, ultrasonic- assisted extraction combined with Box- Behnken design method of response surface methodology was applied for the Kunlun Chrysanthemum polysaccharide extraction.The influence of liquid- solid ratio, ultrasonic time, extraction temperature and other parameters were compared using polysaccharide yield as an index of extraction efficiency.The optimal extraction conditions were as follows: the liquid- solid ratio was60∶1 ( m L / g) , ultrasound extracting time was 53 min, extraction times were two, extraction temperature was 68℃.Under these conditions, the maximum experimental yield of polysaccharide was 9.85%, which was agreed closely to the predicted value 10.07%, the relative error was about 2.18%.