Abstract: Objective To perform expression and to detect immunogenicity of Clostridium difficile Toxin B receptor binding zone(CD3). Methods The clostridium difficile toxin B C terminal repeated gene was amplified by PCR and cloned into the prokaryotic expression vector pET 22b(+), and there combined plasmid pET 22b(+)CD3 was transformed into E.colistrainBL21(DE3).There combined vector was confirmed by digestion with EcoRI/XhoI and sequencing. The E.colistrainBL21(DE3) containing pET22b(+)CD3 was induced with IPTG and analyzed with SDS PAGE. At last metal chromatography method for purification of the recombinant protein, this can be analyzed using the SDS-PAGE method. Results A 71.3 ku protein was acquired after inducing with IPTG and thin layer scanning suggested that CDTBR occupied 34% of the total bacterial protein, 22.7% of the supernatant and 24.9% of the inclusion body. The purifying the recombinant protein is 0.781g/ml by Coomassie brilliant blue G-250 chromatometry method。Conclusions The high expression and purification of clostridium difficile toxin B receptor gene lay a foundation for the further study on CD3 function and clostridium difficile vaccine.