AIM: To investigate the effectiveness of recombinanted retrovirus vector in gene therapy. METHODS: The retroviral vector pLXSN S was constructed and transferred into PA317 by means of electroporation, then HepG 2?RAW264.7 and EL 4 cells were infected with the pseudovirus produced from PA317, which highly expressed HBsAg . HBsAg expression was tested by RT PCR and ELISA. RESULTS: HBsAg was expressed variously in the eukaryotic cells mentioned above. HBsAg ( A value) of the cell supernatants (48 hours) were 0.92,0.53,0.42, respectively. CONCLUSION: The vector used in this study was an effective vector to carry genes of interest to target cells and macrophage, and high level HBsAg was expressed in antigen presenting cell such as macrophage, It indicated that plasmid immunity can induce the B lymphocyte and T lymphocyte response to hepatitis B virus surface antigen by stimulating macrophage. As a vector, it may be useful in the test for gene immunity and gene therapy.