Abstract: Objective: To explore deproteinization process from Agaricus blazei murill polysaccharides by salting-out method.Methods: Salting-out method was used to the deproteinization of polysaccharides from Aaricus blazei murill, the effect of salting-out temperature, salting-out speed, salting-outtime and saturation of ammonium sulfate powder on the protein removal rate and polysaccharide recovery rate were investigated under the influence of the magnetic stirrer, and the conditions were optimized on the basis of single factor experiment through the response surface analysis.Results: Effects of protein removal rate and polysaccharide recovery rate by various factors as order: salting-out temperature > salting-out speed > salting-out time.The best parameters were salting-out temperature of 51 ℃, salting-out speed of 660 r/min, salting-out time of 31 min, saturation of ammonium sulfate powder of 20%, protein removal rate and polysaccharide recovery rate were 80.29% and 79.59%.Conclusions: The experimental results show that deproteinization process from Agaricus blazei murill polysaccharides by salting-outt method is safe and convenient, fast and efficient, and can get higher protein removal rate and polysaccharide recovery rate at the same time.