Abstract: The influence of extraction temperature, time, pH value on the extracted rates of Agaricus Blazei's polysccarides was studied by means of the method of a current, rotational and combinational design of quadratic regression on the basis of determination of the extraction rates of polysaccharides in the article. A quadric regression model of polysaccharides yield to the doses of three factors above was established. The model was significantly fit well and the optimum combination was, therefore, obtained. The responses of the polysaccharides yield to all three single factors and their interactions were discussed. When the extraction processis composed of 100℃, 3 hours and pH 6.3, the polysaccharides yield was pretty high.