The expression and immunogenicity of conserved domain of protein gD were researched for developing antibody detection kit of IBRV virus. Specific primers were designed for the amplification of the gene gD sequence with the immunoglobulin–like domain based on the full length gene gD sequence from bovine herpesvirus, type 1 (GenBank ID NO. NC_001847). The immunoglobulin–like domain gene of gD protein was inserted into plasmid pET–32a after PCR amplication, and was named as pET32a–ΔgD. The expression vector was then transferred into strain E. coli Rosseta (DE3) with aim to induce the recombinant protein. The result showed that 43 000 recombinant proteins were obtained through the analysis of SDS–PAGE, and the relative molecular mass of them were accordance with the theoretical value of recombinant protein gD. After purified from nickel column, the concentration of them was 2.5 mg/mL, with the purity of about 95%. The recombinant proteins were proved of good immunogenicity after experienced the identification of Western Blot and Elisa, which indicated that they could be used as antigen for the development of antibody detection kit of IBR.