Aim To assess the significance of ankle brachial index(ABI) in the type 2 diabetes(T2DM) with peripheral arterial disease(PAD) in lower extremities.Methods 486 T2DM patients were divided into PAD group and Non-PAD group according to the value of ABI(the cut point is 0.9).Two groups were compared and the factors related to ABI were also analyzed.Finally the risk factors of PAD in T2DM were identified.Results Compared with Non-PAD group,the age(62.09±10.53 years vs 56.77±9.83 years,p<0.01),diabetes duration(86.90±51.94 month vs 57.91±57.64 month,p<0.01) and low density lipoprotein cholesterol(LDLC)(3.07±1.01 mmol/L vs 2.71±0.98 mmol/L,p<0.05) were significantly higher,and ABI(0.77±0.15 vs 1.08±0.15,p<0.01) was significantly lower in PAD group.Pearson correlation analysis showed that age and total cholesterol were negatively correlated with ABI.Logistic regression analysis showed that age,diabetes duration,systolic blood pressure(SBP) and LDLC were major risk factors of PAD in T2DM,however,waist hip ratio was a protective factor of PAD.Conclusions ABI is a feasible and reliable index for screening PAD in T2DM patients.Age,diabetes duration,systolic blood pressure and LDLC are major risk factors of low ankle-brachial index in T2DM patients.