1. Recombinant polioviruses have been developed by many research groups for use as vaccine vector because poliovirus induces mucosal immunity as well as humoral immunity through oral uptake. We assessed the potential use of poliovirus as a T-cell epitope carrier. Recombinant poliovirus Vl29 5L was constructed to have a substituted T-helper epitope from the core protein of Hepatitis B virus at eutralization antigenic site 1 on its VPI capsid protein. The recombinant virus replicated less efficiently than type 1 poliovirus Mahoney strain. The Vl29 5L formed a little smaller plaques than the Mahoney strain and showed some 1.25 log unit lower titer at the peak in the one-step growth kinetics though it had similar growth profile to that of the Mahoneystrain. Since Vl29 5L recombinant virus was genetically stable even after 24 successive passages in HeLa cells, the antigenic site 1 on VPI capsid protein was confirmed for its ability of carrying T cell epitope. The genetic stability of Vl29 SL also indicated that recombinant poliovirus can be successfully utilized for the development of the multivalent vaccines.