Abstract: The porcine defensin gene PBD-I was amplified by RT-PCR,then the gene was inserted into expression vector PinPoint^TM Xa-3.Recombinant plasmid named as ppd-1 was transformed into E.Coli JM109,which could effectively produce fusion protein induced with IPTG.The positive clone of PBD-I gene expressed 17kDa fusion protein by SDS-PAGE electrophoresis.Expression of PBD-I gene didn^'t increase distinctly along with time.The expression of PBD-I gene lays a foundation in research on antimicrobial activities and its mechanism of the defensin.