Objective    To express lysostaphic protein in Escherichia coli (E. coli.) and evaluate its biological activities.      Methods    The coding sequence of mature protein obtained by PCR was cloned into the prokaryotic expression plasmid. The target protein was expressed in E.coli. induced by IPTG. The bacteriocidal activities of purified protein were evaluated in vitro by microdilution method.      Results    The recombinant plasmid was identified by DNA sequencing. The protein was successfully expressed in E.coli. and verified by Western blotting. The MIC and MBC of the protein to staphylococcus aureus were smaller than the traditional antibiotics.      Conclusion    We have successfully expressed competent lysostaphic protein in prokaryotic expression system

which has a powerful bactericidal ability against staphylococcus aureus.