Abstract: In this experiment, the hot water extraction of polysaccharides from fruiting body of Grifola frondosa was optimized by response surface methodology.The appropriate times of extraction was determined to be twice by single-factor tests.It was found from the Plackett-Burman design that extraction temperature, ratio of material to liquid and extraction time were three major factors influencing the yield of GFP, and then the optimal response range was approached by the steepest ascent experiment.Lastly, a quadratic polynomial model relating the influencing factors and the yield was established through the Box-Behnken design, and the optimal conditions were: 85℃ of extraction temperature, 2.51h of extraction time, and 1 ∶ 25 of ratio of material to liquid.The yield of 24.423% was obtained by the verification experiment.