Objective:To study the effects of Aloe on metabolism of free radical and anti fatigue.Methods:By building the model of trained mice, the targets of LDH, BUN, Gluc, Hb in the bloods and the activities of SOD,GSH Px,total antioxidation capacity(TAC) and concentration of MDA were tested in the kidney of trained mice. Results: The activities of Hb,SOD,GSH Px, and TAC of Aloe group were higher and LDH, BUN, Gluc, MDA concentrations were lower than those of control group in rest state, which Gluc, TAC and MDA have obviously differences (P<0.05).In immediately after exhaustive exercise, the blood's Gluc, Hb and kidney's SOD ,GSH Px activities and TAC are obvious higher and LDH, BUN,MDA concentration are remarkable lower in Aloe groups than those in control groups. After 24 hour recovery, except SOD and BUN,the others targets have significant difference compared Aloe group with its control group(P<0.05).Conclusion:Aloe could increase the capacity of antioxidation and anti fatigue and reduce the damage of the tissue caused by exercise.Aloe could be studied and exploited as an anti fatigue activity substance.