OBJECTIVE To study the antifatigue effect of Panax japonicus CA Meyer polysaccharides.METHODS Three doses(300,600,1 200 mg·kg-1·d-1) of Panax japonicus polysaccharides and a blank dose were applied to mice for 30 days continuously.The weight,swimming time,the contents of blood urea nitrogen,blood lactic acid and liver glycogen of mice were observed.RESULTS Panax japonics polysaccharides had no effect on mice's weight,all doses of Panax japonicus polysaccharides could significantly prolong swimming time in mice,decreas the contents of blood urea nitrogen and blood lactic acid after strenuous exercise.The mid and hight does of Panax japonics polysaccharides could significantly increase the reserves of liver glycogen.CONCLUSION The study showes that the Panax japonicus polysaccharides from Hubei has anti-fatigue effects.