Macrophage inflammatory protein-3α is a kind of inducible secreted protein which plays an important role in the immune response and inflammation damage in many diseases through the corresponding receptors on a variety of immune cells to produce chemokines.We obtained the ORF of MaCCL20 by RT-PCR,inserted into the expression vector pET-32a,and then transformed into E.coli BL21.We expressed the fusion protein pET-32a-CCL20 after IPTG induction,prepared the polyclonal antibodies and did research on Western blot and antimicrobial activity of it.The experiments show that the fusion protein is highly expressed in the conditions of 37 ℃,0.8 mmol/L IPTG for 4 hours.The SDS-PAGE gel electrophoresis figure shows that the relative molecular weight of the fusion protein is 30 ku which is the same as predicted before.We got a single band after His Bind nickel column purification indicating the high purity of MaCCL20 recombinant protein.The antibacterial experiments show that MaCCL20 recombinant protein has strong antibacterial effects on Staphylococcus aureus,Serratia marcescens,and Aeromonas hydrophila.