Objective To study the value of CT angiography(CTA) and three dimensional contrast enhanced magnetic resonance angiography(3D CE-MRA) in the diagnosis of arteriosclerotic occlusive disease (ASO) of lower limb and evaluate arterial stenosis. Methods Thirty-eight patients clinically suspected ASO were studied with CTA and3D CE-MRA,twenty-two patients underwent DSA at the same time. The degree of seriousness of the stenosis shown by various imaging techniques were analyzed respectively. Results Using the DSA images as the standard reference, the sensitivity and specificity of CTA were 97.3% ,99. 1%, and MRA both were 100.0% in detecting the segments occluded. With regard the detection of segments that had more than moderate stenosis ,the sensitivity and specificity of CT were 99.3% ,97.6% ,and MRA were 97.9% ,96.4%. The degree of seriousness of the stenosis shown by MRA was overestimated than CTA on the segments that had more than moderate stenosis(x2 =5.80,P ＜0. 05). Conclusion CTA and 3D CE-MRA were reliable method in diagnosis of ASO.