Abstract: The purification and activity analysis of Boletus aereus polysaccharides can provide a theoretical basis for the further application and popularization of B. aereus. In the present work,crude polysaccharides of Bronze Boletus was extracted by hot water and then successively purified with DEAE-52 ion exchange column and Sephadex G-100 gel permeadun column. Two polysaccharides,named PB-1A and PB-2A,were obtained after purification. The purity of obtained polysaccharide was determined by specific rotation method and UV spectral scanning. The total reducing power,hydroxyl free radical and DPPH free radical scavenging activity of crude polysaccharides,PB-1A and PB-2A were determined by in vitro antioxidant evaluation system. The results demonstrated that the total reducing power,hydroxyl free radical and DPPH free radical scavenging activity of B. aereus polysaccharides before and after purification showed a dose- dependent manner, with activities being PB-2A>PB-1A>crude polysaccharides of B. aereus.