OBJECTIVE To study the effects of Rhaponticum uniforum polysaccharide on immune function in normal mice and the underlying mechanism. METHOD SRBC and ovalbumin were employed as antigens to be injected to mice, respectively. Three doses of R. uniforum polysaccharide (50, 100, 200 mg x kg(-1) x d(-1)) were given orally for seven days. After the secondary immunization, the level of corresponding antibody and the concentration of serum IL-2, IFN-gamma were determined. RESULT The levels of antibodies (anti-SRBC and anti-ovalbumin) and cytokines (IL-2 and IFN-gamma) in median dose group of R. uniforum polysaccharide were all significantly higher than those in control groups (P <0.05). CONCLUSION R. uniforum polysaccharide could enhance the immune function in normal mice.