Abstract: With different doses ( 200, 400, 800mg /kg·d) of walnut peptides to feed mice, the contents of lactic acid, muscle glycogen, liver glycogen and blood urea nitrogen in serum and tissues were measured.Then the effects on the swimming test in mice were observed.The results showed that after 30 days, compared with control group, the time of swim to exhaust in all test groups were very significantly prolonged ( p < 0.01) , the content of blood urea nitrogen in all test groups were very significantly decreased ( p < 0.01) . The content of lactic acid in high doses group were very significantly decreased ( p < 0.01) , but the content of lactic acid in middle doses group and low doses group were significantly decreased ( p < 0.05) .The content of muscle glycogen in all test groups were very significantly increased ( p < 0.01) , and the content of liver glycogen in all test groups were significantly increased ( p < 0.05) .The results showed that walnut peptide had good anti-fatigue effect.