Abstract: The gene encoding human Cu,Zn SOD was fused to anti carcinoembryonic antigen single chain antibody gene to construct the fusion gene, then was ligated into prokaryotic expression vector pET 22b(+). The fusion gene was expressed in E.coli at high level, and was characterized by SDS PAGE and Western blot analysis. The expression product which accounting for 18% of the total bacteria protein had the CEA binding ability in RIA, and also had the SOD activity by pyrogallol autoxidition assay. So, the Cu,Zn SOD moiety retains substantial enzymatic activity, where the ScFv moiety can delivers the fusion protein to tumor. Cu,Zn SOD is a potential tumor relevant gene, maybe the fusion protein can provide a new pathway to therapy tumors and to meet the damage after radiation or chemical therapy.