Lower extremity atherosclerosis, or lower extremity atherosclerotic occlusive disease, is a chronic arterial occlusive disease of the lower extremity caused by atherosclerotic lesions of the arteries. Lower extremity atherosclerosis gradually produces lumen occlusion due to atherosclerotic plaque, arterial middle layer degeneration and secondary thrombosis, resulting in ischemia of the lower extremity. The main clinical manifestations are coldness, numbness, pain, intermittent claudication, loss of arterial pulsation, nutritional disorders of the limb tissues, and ulceration or gangrene of the toes or feet. The etiology is not fully understood. Hyperlipidemia, hypertension, smoking and diabetes mellitus are the risk factors, and it is more common in men over 45 years of age. The pathogenesis includes endothelial damage and smooth muscle cell proliferation, lipid metabolism disorder in the arterial wall, and blood flow impact. The manifestation is atherosclerotic plaque in the intima, degeneration or calcification of the intima, and secondary thrombosis in the lumen, which eventually narrow the lumen or even blockage. In case of secondary thrombosis or plaque dislodgement, distal artery embolism may result. The severity of symptoms is related to the progression of the disease, the degree of arterial stenosis and side branch compensation. The femoral, popliteal and posterior tibial arteries and the dorsalis pedis artery of the diseased limb are weak or not palpable. Ultrasound Doppler, CTA with arteriography, DSA, and MRA are helpful in diagnosing this disease.