This Evaluation was aimed to assess the effect of soybean peptide on relieving physical fatigue in mice and explore its mechanism. Two animal experimental models of acute fatigue and D-galactose subacute aging were established. The ICR mice were divided into low-dose (0.25 g/kg)， medium-dose (0.5 g/kg) and high-dose (2.5 g/kg) groups of soybean peptide. The load swimming time (WLS)， serum urea nitrogen (BUN)， blood lactic acid (LD)， glycogen， glycogen synthetase (GS)， total peroxidase (T-SOD)， malondialdehyde (MDA)， and creatine phosphate kinase (CPK) in serum and liver of mice were researched. The results showed that in the two models， each dose of soybean peptide could significantly increase exhaustive swimming time and decrease BUN content， but had no effect on MDA content and CPK activity. The activity of T-SOD in the liver of mice was increased by all doses of soybean peptide， and the degree of improvement in the D-galactose subacute aging model was less than that in the acute fatigue model. In the subacute model of D-galactose， low doses of soybean peptides(SP-L) had no effect on the elimination of LD content， and all other doses of soybean peptides in the two models could reduce LD content. Under the acute fatigue model， liver glycogen storage could be increased by soybean peptides but it had not changed significantly in the D-galactose subacute aging model. In conclusion， under the acute fatigue model， soybean peptide can relieve physical fatigue mainly by increasing the activity of T-SOD， reducing fatigue products， and increasing the accumulation of energy substances. The fatigue alleviating pathway of the two models was similar， but the soybean peptide in the D-galactose subacute aging model had no effect on the accumulation of energy substances， and the fatigue alleviating effect was insignificant.