Aim To investigate the clinical application of ankle-brachial index(ABI) in the treatment of peripheral arterial disease in the patients with type 2 diabetes mellitus. Methods 112 type 2 diabetic patients with peripheral arterial disease were randomly divided into drug treatment group(n=62) and interventional therapy and drug treatment group(n=50).All patients were checked for ABI by automatic analysis system of angiosclerosis. Results ABI was less than 0.90 in type 2 diabetic patients with peripheral arterial disease before therapy.ABI was increased in type 2 diabetic patients with peripheral arterial disease after interventional therapy and drug treatment(P<0.05).ABI was not increased in type 2 diabetic patients with peripheral arterial disease after drug treatment(P>0.05). Conclusion ABI is significant in type 2 diabetic patients with peripheral arterial disease who had taken the interventional therapy.