OBJECTIVE： To study the effect of polysaccharides of Radix scrophulariae on immune function in mice under normal physiological and hypoimmunical state. METHODS： 80 mice were randomly divided into normal group， model group， treatment high-dose， medium-dose， low-dose groups and physiological high-dose， medium-dose， low-dose groups， 10 in each group. Mice in normal group and model group were received distilled water （10 mL/kg） intragastrically， treatment high-dose， medium-dose， low-dose groups and physiological high-dose， medium-dose， low-dose groups were administrated 0.16， 0.08， 0.04 g/kg drug， ig， once a day， for 7 d. From the third day， mice in model group and treatment high-dose， medium-dose， low-dose groups were respectively received cyclophosphamide （100 mg/kg）， ip， for 4 d to induce hypoimmunical model. Carbon clearance test was adopted to determine the carbon clearance indexes and organs （chest， spleen） indexes of mice. Another 80 mice were grouped with the same administration， serum half hemolytic value （HC50） was determined after compressed Mianyang red blood cell sensitization. Then another 80 mice were grouped with the same administration， 1％ dinitrofluorobenzene method was used to induce delayed hypersensitivity in mice； its ear swelling was determined， as well as IL-2， IL-4， immunoglobulin G （IgG）， immunoglobulin M （IgM）， γ-interferon （IFN-γ） contents in serum， and the proliferation in vitro of splenic lymphocytes were detected. RESULTS： High-dose polysaccharides can promote the increasing of immune organ and carbon clearance indexes （P＜0.05）； enhance the intensity of delayed type hypersensitivity （HC50 increasing） （P＜0.01） and improve the decreasing of serum hemolysin in model mice （P＜0.01）； promote the splenic lymphocytes proliferation and increase IL-2， IL-4， IgG， IgM， IFN-γ contents in serum （P＜0.05 or P＜0.01）. CONCLUSIONS： Polysaccharides can enhance the immune function in mice under normal physiological and hypoimmunical state induced by cyclophosphamide.