Abstract: Objective To study the lipid peroxidation-related changes of telomere length in patients with Alzheimer’s disease（AD）.Methods Forty AD patients（experimental group） and 59 healthy subjects（control group） were enrolled in this study.Concentration of 8-iso-prostaglandin F2α（8-iso-PGF2α） in urine and telomere length in peripheral mononuclear cells（including average length of telomere and its distribution） were measured,respectively.Results The urinary 8-iso-PGF2α level was statistically higher in AD patients than in controls（71.68±2.60）ng/mmol vs（46.90±1.88）ng/mmol creatinine（P＜0.001） with no difference observed in the mean length of telomeres.However,the ratio of slightly longer telomeres（4.4-9.4kb） was increased,while that of short telomeres（＜4.4kb） was decreased in AD patients.Conclusion The oxidation stress level is statistically higher in AD patients than in controls.The distribution of telomere length is related with the oxidation stress-related change.The shortest telomeres are more sensitive to oxidation stress.