There are two major blood supply systems to the brain, the carotid artery supply system and the vertebrobasilar artery supply system, each with a different division of labor. The carotid blood supply system includes the bilateral internal carotid arteries, which mainly supply blood to the anterior 2/3 of the cerebral hemisphere and part of the mesencephalon, while the vertebrobasilar blood supply system includes the bilateral vertebral arteries and their upward convergence into the basilar arteries, which mainly supply blood to the posterior 1/3 of the cerebral hemisphere (occipital and temporal lobes of the cerebral hemisphere), cerebellum, and brainstem. Narrowing or occlusion of the cerebral arteries is an important cause of ischemic cerebral infarction. The causes include atherosclerosis, aortitis, fibromuscular dysplasia, surgery and radiation injury, among which atherosclerosis is the most common, and the stenosis caused by atherosclerosis mostly invades the bifurcation of the carotid artery, the beginning of the internal carotid artery and the beginning of the vertebral artery. Clinical manifestations of cerebral artery stenosis vary depending on the site of stenosis. Clinical carotid artery stenosis may have precursors of carotid artery insufficiency, such as transient ischemic attack (TIA), small retinal artery embolism or non-disabling ischemic stroke, and may present with symptoms such as hemiparesis, aphasia, hemianesthesia, and monocular darkness. Vertebral artery stenosis has manifestations of inadequate vertebrobasilar supply such as vertigo, blurred vision, diplopia, bilateral dark haze, ataxia, and syncope. Magnetic resonance angiography (MRA), CT angiography (CTA), and ultrasound can show the site and extent of lesions, morphological features, degree of calcification, and the presence of ulcer formation, etc. Intracranial ultrasound Doppler can also evaluate intracranial hemodynamic information and the function of the Willis ring. Angiography is the gold standard for evaluating arterial stenosis and planning further treatment. It can assess both the aortic arch and the intracerebral circulation, and can accurately evaluate multiple arterial stenoses, types of collateral circulation, and the presence of other vascular lesions. Current treatments include medical medication, surgical carotid endarterectomy and interventional therapy. Interventional treatments include percutaneous transluminal angioplasty (PTA) and stenting (CAS), which are becoming more and more accepted by patients because of their minimally invasive and efficient nature. The key to current treatment is the early detection of cerebral artery stenosis, i.e., intervention before it causes a large cerebral infarction, in order to prevent the problem before it occurs. Once a large cerebral infarction occurs, even if the narrowed or occluded vessel is opened, it is difficult to restore the lost function of the patient.