Abstract: OBJECTIVE: To assess the relation of aging and oxidative damage caused by γ_rays． METHODS: 60 mice were divided into 4 groups：group A was control group; mice of group B were treated with intraperitoned D_galactose; mice of group C were irradiated by γ_rays; mice of group D were treated with D_galactose and irradiation. The activity of SOD，contents of MDA and lipofuscin and AGEs in blood serum were determined，the expression in of β_galactosidase by staining was measured at the end of 80 days' experiment． RESULTS: Compared with group A, the activity of SOD was decreased in group B(P<0.05)，the level of AGEs and contents of MDA and lipofuscin increased in group B(P<0.05), also the β_galactosidase activity was positive. The activity of SOD was decreased in group C(P<0.05)，contents of MDA and lipofuscin increased in group C(P<0.05),also the β_galactosidase activity was positive, but no significant difference was found in the level of AGEs in group C(P>0.05). Compared with group B, the activity of SOD was decreased in group D(P<0.05)，the level of AGEs and contents of MDA and lipofuscin were increased in group D(P<0.05), also the β_galactosidase activity was raised. CONCLUSION:Aging was enhanced by oxidative damage caused by γ_rays.

Key words: aging, free radicals, oxidative damage