Abstract: Objective To study the alleviative effects of soyisoflavone and soyasaponins on physical fatigue in mice.Methods 120 male ICR mice were randomly divided into two batches according to body weight,and each batch was divided into five groups:normal control group,soyisoflavone group in low dosage,soyisoflavone group in high dosage,soyasaponins group in low dosage,and soyasaponins group in high dosage.After the mice were orally administered soyisoflavone or soyasaponins in low dosage and high dosage respectively for 30 days,loaded swimming time,serum urea nitrogen and glycogen in liver and muscle were determined.Results Soyisoflavone and soyasaponins significantly prolonged the loaded swimming mean time of mice,while soyisoflavone and soyasaponins obviously decreased serum urea nitrogen level after swimming.At the same time,soyisoflavone and soyasaponins showed an evident incremental effect after swimming on glycogen in liver and muscle.Conclusion Soyisoflavone and soyasaponins can alleviate physical fatigue,and the alleviative effects between soybean isoflavone and soybean saponins are similar.