Objective.To study the therapeutic T cell vaccine for the treatment of chronic hepatitis B by improving the cellular immunization of HBsAg vaccine with the coexpression of the preS1（1-42）and the Core（1-144）anti-gen of HBV in E.coli.Methods.The genes of HBcAg （1-144）and preS1（1-42）were amplified and fused by PCR.This fused gene was inserted in the prokaryotic expression vector pET-11d and expre ssed in E.coli.Results.It was showed by SDS-PAGE that the pr otein molecular weight of the coexpr ession product was about 20kD

20%of all bacteria prote in.The monoclonal antibodies again st core and preS1antibody could re-act with this fused protein by Western-blot technique respectively.The fused gene was verified by sequencin g.Under the immune electron microscop y

this fused protein is typical particles of HBcAg but in an aggregated form.Conclusion.The results might aid for studying T c ell immunotherapeutic vaccine for c hronic hepatitis B.