Objective:To construct inhibin expression vector with high immunogenicity.Methods:S gene with enzyme site sequence of EcoR I and Nde I was amplified by PCR from pCMV-S;Inhibin(1-32)gene with enzyme site sequence of Nde I and Hind III was cut from pUI;S and inhibin(1-32)gene were directly inserted into pcDNA3.1(-)and the recombinant pCIS was identified by restriction endonculease digestion and sequencing;then pCIS was transfected into HeLa cells.SDS-PAGE and ELISA was employed to detect the cell product.Rats were immunized with inhibin fused expression plasmid pCIS and ELISA was used to detect the blood antibody against inhibin.Results:The recombinant eukaryocyte expression vector of inhibin was constructed.The sequence of the insert was identical to designed gene.Fusion protein weight was about 29 kD and it had inhibin immunologic activity.Rats immunized with pCIS induced antibody against inhibin.Conclusion:The fusion gene expression vector was successfully constructed,and it set up the basis of inhibin gene immunization to induce multiple bear for single birth animals.