To obtain fusion protein of Mycobacterium bovis with high purity, the recombinant prokaryotic expression vector for Mb2277 gene was constructed and the immunogenicity of its products was initially investigated in the present study.A pair of primer was designed according the gene sequence Mb2277 from the genomic DNA of M.Bovis in GenBank. and was amplified by PCR using DNA of M.Bovis 93006 strain as template. The PCR product and pET-28a(+) was then digested by BamHⅠ and EcoR Ⅰdouble enzyme. To constructed a prokaryotic expression plasmid, the purified Mb2277 was cloned to pET28a(+). Then the recombinant plasmid was transformed into competent cell of E.coli BL21(DE3).The bacteria were induced by IPTG and its lysates were analyzed by SDS-PAGE and Western-blotting. In this way, the prokaryotic expression plasmid for M. bovis Mb 2277 protin was obtained, and a expression band with molecular of 25 ku could be found in SDS-PAGE analysis. As demonstrated by Western blotting this expression product showed excellent reactivity with rabbit immune sera against M. bovis.