The aim of this work was to evaluate the antioxidant activity and polysaccharides content in mycelial pellets of Agaricus blazei and Agaricus bisporus by liquid state fermentation.The EC50 values of Agaricus blazei in scavenging effect on DPPH radical,reducing power,Ferrous Ions' chelating capacity and superoxide anion's scavenging capacity were respectively 4.16 mg /mL,8.28 mg /mL,6.54 mg /mL and 6.16 mg /mL.The EC50 values of Agaricus bisporus in scavenging effect on DPPH radical,reducing power,Ferrous Ions' chelating capacity and superoxide anion's scavenging capacity were respectively 2.56 mg /mL,22.48 mg /mL,14.06 mg /mL and 7.16 mg /mL.These results showed that the antioxidant activity in mycelia pellets of Agaricus blazei was superior to that of Agaricus bisporus.The polysaccharide content of Agaricus blazei was 9.85%,while the Agaricus bisporus was 8.42%.