Abstract:The effects of protein removal from polysaccharide of Pleurotus ostreatus were analyzed by comparing the three methods of Sevage， hydrochloric acid-ethanol isoelectric point and TCA with protein removal rate， polysaccharide retention rate and comprehensive index as evaluation index. The result showed that protein re－ moval rate of polysaccharide by the method of Sevage was the highest， and followed by the method of TCA. The best way for polysaccharide retention rate was the method of hydrochloric acid-ethanol isoelectric point， and second was TCA. And in consequence the TCA method was the most effective one among the three ways by con－ sidering the two factors of protein removal rate and polysaccharide retention rate. A regression equation of the protein removal from polysaccharide of Pleurotus ostreatus by the way of TCA was obtained using the Box -Behnken test design， and then the optimal conditions of the process for protein removal was established by re－ sponse surface analysis， which was TCA concentration 5.6 %， processing time 33 min， and temperature 48 ℃. Under these conditions， the average of comprehensive evaluation was 83.96 %， the protein removal rate and polysaccharides retention rate was 89.5 % and 78.4 %， respectively.