Abstract: The antimicrobial activity of Ganoderma lucidum fermentation products （mycelium and fermentation broth）isolated from Leye Tiankeng Group in Guangxi was studied by using filter paper and double dilution method,in order to provide reference for developing anti-corrosion and food preservation products.The results showed that both mycelium extract and fermentation broth extract contained antibacterial active substances,and ethyl acetate extract of fermentation broth had the strongest antibacterial activity against all 10tested microbes.The 30%ethyl acetate component（B5）of ethyl acetate extract from fermentation broth had the highest antibacterial activity,and the diameters of antibacterial zone were basically the largest.The minimum inhibitory concentration（MIC）value of B5against Micrococcus luteus was 25mg·mL^-1,the MIC value for Escherichia coli,Bacillus subtilis,Proteus vulgaris,Staphylococcus aureus and Candida albicans were 50mg·mL^-1,the MIC value for Saccharomyces cerevisiae was 200mg·mL^-1,and the MIC value for Aspergillus niger,Aspergillus oryzae and Trichoderma viride was 400mg·mL^-1.