Abstract: Objective To investigate the effect of different types of fermented tea leaves on D-galactose-induced senile mice. Methods Seventy male mice were randomly divided into control group,D-galactose control group,green tea group,oolong tea group,black and dark tea group,and vitamin C(vit C)group.The oxidant damage model was established by consecutively injecting D-galactose into the hypoderm of the mice for 30 days.At the same time,the mice in four kinds tea groups and vit C group were administered orally with tea solution(2 g/kg·bw·d)and vit C(10 mg/kg·bw·d). Thirty days after the treatments,the mice were sacrificed and four organ-indexes were examined and the activities of super oxide dismutase(SOD),catalase(CAT)and total anti-oxidative capacity(T-AOC)in serum,liver and brain tissue of the mice were measured. Results The organ-indexes for liver,brain,spleen,and thymus gland in green tea group were higher than those of D-galactose-induced aging mice model group(P<0.05).In the oolong tea group,only the contents of SOD(5.51±0.66 U/mL),T-AOC(14.87±0.57 U/mL)in serum increased(P<0.05).The contents of SOD,CAT and T-AOC in serum,liver and brain tissue in green,black,and dark tea group were increased(P<0.05).The antioxidant effect of the green tea was the strongest and that of the black and dark tea were similar. Conclusion Different types of fermented tea leaves possess strong anti-oxidant effects on D-galactose-induced oxidative damage in vivo and the effect of green tea is the strongest.