In this study, the extraction of polysaccharides from Pleurotus djamor and its decolorization and deproteinization were investigated. The optimal extraction conditions were obtained by RSM. Macroporous anion exchange resin D315 was used to decolorize polysaccharides and moreover Sevage method was adopted to deproteinize it. The optimum extraction conditions were as followed:temperature 95℃, time 3.9h, and the solid-liquid ratio 1∶30.6 (g∶mL). Under these conditions, the yield was 13.44 %. Decoloration rate of D315 was 81.37% and polysaccharide retention rate was 82.21%. While the deproteinization rate was 61.39% and polysaccharide retention rate was 93.29%. Pleurotus djamor polysaccharide with a high yield and a low content of pigment and protein could be obtained by the established extraction process, decolorization and deproteinization together.