Purpose: This study was designed to investigate enhancing the immunogenicity effects of Platycodon grandiflorum(PG) on adaptive immune system. Methods: To investigate the effect of PG as an adjuvant, we used the ovalbumin (OVA) as an antigen at first. The proliferation of lymphocytes, the antibody titer, the subisotypes of antibodies and the production of cytokines were measured. Results: The proliferation of lymphocytes and the antibody titer were increased after PG treatment. The increased subisotypes of antibodies were IgG2 and IgG3 induced from T1-helper cells. However IgE induced from T2-helper cells was decreased. The production of cytokines derived from T1-helper cells was increased but that from T2-helper cells was decreased. Conclusion: It is supposed that PG has an immunogenicity effect as an adjuvant on adaptive immune system.