Objective To rational design HBV therapeutic vaccine candidate and evaluate their specific immunity to HBV in mice.Methods Based on our previous data of HBV protein vaccine consisting of S-PreS1 fusion particle.We first construct a novel DNA vaccine candidate,pVRC-HBSS1,which consisting of S (an:1-223) and PreS1 (an:21-47) fuse gene,then confirm the expression of the DNA vaccine by Western blotting,and followed by vaccination using prime boost strategy,ie,Intradermal injection of DNA vaccine with gene electroporation (EP) in BALB/c mice after twice injection of different HBSS1 protein vaccines (combination with different adjuvants).The immune response was measured by ELISA and IFN-gamma ELISPOT.Result The novel DNA vaccine candidate could effectively express in vitro,boost with single intradermal injection of HBV DNA vaccine via EP can significantly enhance the surface antigen (S)-specific cellular immune responses (IFN-γ,ELISpot analysis) and PreS1-specific antibody levels,especially in the group primed with protein vaccine in combination with alum adjuvant.Conclusion Boost with the novel HBV DNA vaccine followed prime with HBV protein vaccine could induced a higher anti-HBV T cell response in mice than vaccination with the HBSS1 particle-like protein vaccine only.This prime-boost vaccination may serve as a promising way to develop and optimize the novel HBV therapeutic vaccine.