Objective To get the gene encoding extracellular domains of gB protein of B virus and analyze its expression in the eukaryocyte cell. Methods synthesizing gene fragment encoding extracellular domains of gB protein of B virus was by using synthesis gene, then digested with the restriction endonucleases BamHⅠand NotⅠand inserted into eukaryotic expressing vector pEGFP-N3. pEGFP-N3-GB_合 was transfected into 293 cells. After protein extraction, the expression of gene was detcted by western blotting, and the cellular localization of the gene was analyzed by immunofluorescence and laser scanning confocal microscopy. Results pEGFP-N3-GB_合 were expressed in 293 cells and on the cell membrane. Conclusion eukaryotic expressing system can produce specific antigen recombination protein of B virus gB protein and express on the cell membrane.