Abstract: To maintain the native conformation and antigenicity of hemagglutinin （H） of canine distemper virus, the H gene which referred to HLJ2-07 strains was accurately amplified by RT-PCR and cloned into pFastBac^TMHTA vector. The recombinant plasmid was successfully transformed into E.coli DH10Bac^TM competent cell and constructed shuttle vector, which was transfected into Sf9 cell to save baculovirus expressing destined protein. To determine the antigenicity of recombinant protein, Western blotting analysis was used to detect the interesting protein. Furthermore, the identification and characterization of B cell epitopes were predicted and analyzed by related software and online websites. The result demonstrated that the fusion protein generated by recombinant baculovirus was reacted with both anti-His tag monoclonal antibodies and canine distemper virus positive serum by Western blotting test, which showed that this protein had sufficient antigenicity. In addition, B cell epitopes were selected by between Swiss-model and online websites for consistent sequences to improve predictive accuracy, whereas the possible sites were 175 to 195, 240 to 250, 365 to 380, 480 to 508 and 526 to 555. These efforts served as a strong foundation for the development of diagnostic kits，the production of monoclonal antibodies and selection of protein epitopes.

Key words: canine distemper virus; hemagglutinin protein; baculovirus expression system; B cell epitopes