This invention relates to a HB vaccine enhancing protein, its gene, gene engineering method for expressing this protein, and the application of this method. The cDNA of this protein, which is screened out from human liver cDNA library, is sequenced and then cloned into prokaryotic or eukaryotic (animal or plant) cell for expression of protein coded by the cDNA (for example, cloning into prokaryotic expression carrier and expression in E. coli) and purification of the protein. The protein obtained, when used with HB vaccine, can significantly increase the effect of the vaccine, the immune power of HBV carrier, and the titer of antibody. The protein can be used as an adjutant to HB vaccine.
