Abstract: The plant expression vector pBRSAg was constructed, which contained all elements for plant expression, such as CaMV35S promoter, both left and right border sequence for T-DNA in Agrobacteria, plant reporter gene gus, and plant screening marker gene hpt, and was suitable for transformation via Agrobacteria. The recombinant binary vector pBRSAg was mobilized into Agrobacterium tumefaciens strain LBA4404 cells by using the freeze-thaw method. Tobacco leaf discs were transformed by A. tumefaciens and plants were regenerated on selection medium. GUS staining and PCR test of the plants were positive. It was initially shown that the HBsAg gene was expressed in transgenic tobacco plants.

Key words: hepatitis B surface antigen gene, expression vector, tobacco, plant vaccine