Abstract: The aim of this work was to investigate the anti-fatigue and protective effect of exhausting exercise-induced myocardial damage of aqueous extract from Lycium ruthenicum Murr.. One week of adaptive feeding,then 60 male Kunming mice of were randomly divided into sedentary control group,blank control group,positive control group,low-dose group,mid-dose group and high-dose group,with 10 mice in per group. The mice in sedentary control group and blank control group were administered physiological saline,the mice in positive group were administered American ginseng powder at 0.05 g/mL,the mice in low-dose group,mid-dose group and high-dose group were administered aqueous extract from Lycium ruthenicum Murr. at 0.01,0.1,0.15 g/mL,the drug doses were 0.1 mL/10 g. Every group was given the appropriate intervening measures. The weight of the mice in each group was measured immediately after the last gastric perfusion. Exhaustive swimming time of mice in each group(except sedentary control group)were measured. The blood lactic acid,blood urea nitrogen,the activity of lactate dehydrogenase,muscle glycogen and liver glycogen of mice in each group were measured for 30 minutes after swimming. Meanwhile,myocardium samples were subjected to histological examination. The results that aqueous extract from Lycium ruthenicum Murr. could extend significantly weight-loaded swimming time of mice(p<0.05),decrease effectively blood lactic acid and blood urea nitrogen(p<0.05),enhance observably the activities of LDH,and that aqueous extract from Lycium ruthenicum Murr. could increase evidently in liver and muscle glycogen deposition(p<0.05),improve intercellular space and the degree of uniformity of cardiac myocyte distribution in exhausted mice. The results indicated that aqueous extract from Lycium ruthenicum Murr. had the effect of resisting fatigue and protecting sports myocardium.