The flavonoids were extracted from Stropharia rugoso-annulata Farlow and the antibacterial activity on E.coli,Penicillium and S.cerevisiae was studied in this paper.The extraction conditions of flavonoids were optimized by orthographic experiment.The extraction rate could get to 7.94‰ under the optimum extraction conditions including ethanol concentration of 95%,material ratio of 1∶90,60℃,and 120min.The growth of E.coli and Penicillium could be inhibited by 40g/L of the flavonoids from Stropharia rugoso-ann...