Abstract: Computed tomography angiography(CTA)is an increasingly attractive imaging modality for assessing lower extremity arteriosclerosis obliterans. This technique has obvious advantage because it is a non-invasive and simple and convenient method than other ways. Previously, digital subtraction angiography was the only established reliable imaging technique to quantify atherosclerotic disease; however, CTA may now challenge this old " gold standard". Multidetector computed tomography enables imaging of the entire arterial tree non-invasively. Optimal technical considerations for performing Multidetector CTA are essential for accurate diagnosis of atherosclerotic diseases. The essential issue of radiation dose reduction during the processing of CTA is solved by the optimization of contrast agent and instrument parameter. CTA will certainly be a perfect technique for the diagnosis of lower extremity arteriosclerosis obliterans along with the rapid progress of Computed tomography.