Optimal conditions for the extraction of black fungus polysaccharides were 350 W, 5, 35 min and 90 ◦C, for ultrasonic power, ratio of water to sample, extraction time and extraction temperature, respectively. Gas chromatography (GC) analysis showed that black fungus polysaccharides contained glucose, xylose, mannose and ribose. Their molar percentages were , , and , respectively. FT-IR and NMR analysis showed typical chemical structure of black fungus polysaccharides. In animal experiment, high fat diet feeding for 29 days markedly reduced myocardium and blood antioxidant enzyme activities and enhanced lipid peroxidation level. Administration of black fungus polysaccharides had significantly enhanced myocardium and blood antioxidant enzyme activities and.