Abstract: In order to optimize the extraction process of white hypsizygus marmoreus polysaccharide, the single-factor experiments were carried out with extraction temperature, extraction time and ratios of water to material as single factors.On the basis of single-factor experiments, response surface methodology was employed to establish mathematic model, analyze experimental data, optimize and verify the extraction process parameters of white mushroom polysaccharide. The results of optimum extraction conditions were as follows: extraction temperature 80 ℃, extraction time 4.2 h and ratio of water to raw material 35∶ 1 ( m L/g) .Under these conditions, the average extraction yield was 6.41%.