Objective To study the effects of tea polyphenols on activator protein 1 and cell cycle of human liver cancer cell. Methods An activator protein 1 luciferase reporter gene was constructed and the activities of activator protein 1 were measured. The expression changes of cyclinDl and cyclin - denpendent kinase 4 were studied by the immunity organization chemistry method, cell cycle was analyzed by flow cytometry, Results The activities of activator protein 1 were repressed, the experession of cyclinD1 and cyclin - denpendent kinase 4 was reduced, Gt arrest was induced by tea polyphenols in cell...