Objective： To explore the alleviating physical fatigue effect of corn peptide in mice. Methods： The mice were divided into the control group（casein） and the low， medium and high dose group by their weight. Mice in three dose groups were orally given corn peptide samples for 30 d with various dose. The time of weight loaded swimming （WLS）， hepatic glycogen level， serum urea and blood lactic acid levels after swimming were observed sequentially. Results： Compared with control group， the result showed that the corn peptide could significantly improve the load swimming time in three dose groups （P＜0.05）. The hepatic glycogen contents in medium dose group had a significant increase （P＜0.05） as well as decrease remarkably in serum urea nitrogen contents after swimming（P＜0.05）， however the blood lactic acid level and AUC in three dose groups proved no statistical significance（P＞0.05） after swimming. Conclusion： Corn peptide has an effect on alleviating physical fatigue in mice with in a certain dose.