Abstract: Objective:To investigate the immunomodulation of the crude polysaccharides from xigui on exercise-induced fatigue mice. Methods:Mice were randomly divided into 5 groups:Normal control group,model control group high-,medium-,and low-dose of crude polysaccharide from xigui group(100,200,400 mg/kg). Each mice was administered with corresponding drugs everyday by gavage,and then was forced to swim until fatigue for successive 10 days. The effects of polysaccharide from xigui on the carbon particle clearance index and the organ index of each mouse,the concentrations of BUN,IL-4,IFN-γ,ALB,IgG and ALT in mice’s serum were detected to evaluate its immunomodulatory effect on exercise-induced fatigue mice. Results:The low,middle and high dose group of crude polysaccharide from xigui had certain immunomodulatory effects on the exercise-induced fatigue mice,and the middle dose group(200 mg/kg)had the best effect. The carbon particle clearance index and phagocytosis coefficient were significantly upregulated in the low dose group(P<0.05)and middle dose group(P<0.01). Both middle and high dose of crude polysaccharide from xigui significantly upregulated thymus and spleen mass and index of mouse(P<0.01). Medium and high dose of crude polysaccharide from xigui significantly reduced the content of BUN in the serum of mice(P<0.01). Middle dose(P<0.01)and high dose(P<0.05)of crude polysaccharide from xigui obviously down-regulated the content of IL-4,increased the content of IFN-γ,and decreased the ratio of IL-4/IFN-γ(P<0.01). Middle dose of drug increased the levels of IgG(P<0.01). Low,medium and high dose of crude polysaccharide from xigui down-regulated liver mass of exercise fatigue mice(P<0.01 or P<0.05),and middle and high dose significantly increased the content of ALB and decreased the content ALT(P<0.05 or P<0.01). Conclusion:By regulating immune function and balance and reducing liver damage,crude polysaccharide from xigui plays an active role in immunomodulation of exercise-induced fatigue.