Abstract: In the approaches of constructing recombinant vaccines based on avian vasoactive intestinal peptide (VIP), human hepatitis B core antigen (HBcAg) cDNA was chosen as the carrier for the purpose of enhancing immunogenicity of goose VIP. The VIP cDNA sequence and the 1 st to 435 th bp sequence of HBc cDNA (coding for 1 st to 145 th amino acid residues of HBcAg) were respectively amplified and inserted into BamH I\ Pst I and Nhe I\ BamH I cloning sites of plasmid pRSET A to produce plasmid pHBc VIP containing the HBc VIP fusion gene, which would express a fusion protein with VIP positioned posterior to the 145 th amino acid residue of HBcAg. Then the 1 st to 225 th bp sequence of HBc cDNA amplified, and the sequence starting from 244 th bp of HBc cDNA to the end of VIP sequence of pHBc VIP was amplified, digested with EcoR I, ligated and then amplified were respectively inserted into the BamH I\ Pst I and the Pst I\ Hind III cloning sites of plasmid pBSKS +/- to construct plasmid pVIP HBc, which contains a fusion gene with VIP sequence inserted into the middle of HBc cDNA, and coding for a fusion protein with VIP sequence inserted into the 75 th and 83 rd amino acid residue positions of HBcAg.