Abstract: Aflatoxin B₁ (AFB₁) is a type of fungaltoxin with strong toxicity and strong carcinogenicity. To screen degrading bacteria of AFB₁, co-culture of fungi strains which were stored in laboratory and AFB₁ was carried out and the strains with the highest degradation rate were chosen. Species of the chosen strains were determined through morphology and ITS rDNA analysis. After separation of different components (bacterial suspension, thalli, spore suspension and fermentation liquor) in strains, the effective components for AFB₁ degradation were explored, and the effective components thalli was broken for further investigation. Results showed that the AFB₁ degrading rates by Penicillium herquei MD1 bacterial suspension cultured by 72 h and the unbroken thalli were 98.15% and 28.20%, respectively. The degradation of AFB₁ was better after the fragmentation of the thalli, and the degradation rate of AFB₁ was 55.40% after 24 h of incubation. Therefore, the active components in MD1 bacterial suspension and thalli can degrade AFB₁ effectively. The screened MD1 expands the degrading bacterial library of AFB₁ and provide some references to biological degradation of AFB₁.