Abstract: In vitro, Ginkgo Biloba Enocarp Polysaccharides (GBEP)could promote the T lympho cyte proliferation by spleen cells induced by ConA form normal BABL/c mice and s180 bearing BABL/c mice. It could also antagonize the suppressive effect of hydrocortisone (HC) on proliferation of mouse spleen cells induced by ConA. In vivo i GBEP could enhance the rate of spleen T lymphocyte in mice. It could also antagonize the suppressive effect of cyclophosphamide (Cy) on the delayed cutaneous hypersensitivity (DCH) in duced by DNCB in mice.