The immunomodulatory effects of the polysaccahride extracted from Cyathula officinalis Kuan were evaluated by using normal mice immunocytes with respect to cytotoxicity, lymphocytes proliferation, NK activity and ability of peritoneal macrophage phagocytizing neutral red. The results showed that the polysaccharide had no cytotoxicity, but could promote B lymphocytes proliferation (P<0.01), and could also enhance NK activity (P<0.05) and the ability of peritoneal macrophage phagocytizing neutral red (P<0.01)...