The hypouricemic actions of exopolysaccharide produced by Cordyceps militaris (EPCM) in potassium oxonate-induced hyperuricemia in mice were examined. Hyperuricemic mice were administered intragastrically with EPCM (200, 400 and 800 mg/kg body weight) or allopurinol (5 mg/kg body weight) once daily. Serum uric acid, blood urea nitrogen and liver xanthine oxidase (XOD) activities of each treatment were measured after administration for 7 days. EPCM showed dose-dependent uric acid-lowering actions. EPCM at a dose of 400 mg/kg body weight and allopurinol showed the same effect in serum uric acid, blood urea nitrogen and liver XOD activities in hyperuricemic mice. An increase in liver XOD activities was observed in hyperuricemic mice due to administration of EPCM at a dose of 200 mg/kg body weight. EPCM at a dose of 800 mg/kg body weight did not show significant effects on serum uric acid and XOD activities. We conclude that EPCM has a hypouricemic effect caused by decreases in urate production and the inhibition of XOD activities in hyperuricemic mice, and this natural product exhibited more potential efficacy than allopurinol in renal protection.