Abstract: Objective To purify and renature the MarA protein of shigella flexneri 2a and study its biological activity.Methods His-tag MarA fusion protein was expressed in Escherichia coli as inclusion body with IPTG induction.Cells were then harvested,sonicated and centrifuged,and the inclusion bodies were isolated and purified by Ni2+-high performance affinity chromatography,and refolded in the presence of GSH/GSSH.The purity of His-MarA was identified by thin-layer scanning analysis.Results The purity of the MarA rote in was more than 90% after Ni2+-high perform ance aff inity chromatog raphy.Conclusion The method of fusion prote in His-MarA purification from the inclusion body was developed for further study on MarA.Western blotting showed pecific Ag-Ab binding band between the antiserum and the Mar Afusion proteins after the prote in was purified and renatured.