The blood supply of the internal capsule is mainly from the middle cerebral artery, a branch of the bean artery. The middle cerebral artery is a direct continuation of the internal carotid artery with a high blood flow, and the pressure in the lumen of the bean-shaped artery, which branches vertically from the middle cerebral artery, is high, and it is very easy to form microaneurysms, and when rupture and hemorrhage occurs due to a sudden rise in blood pressure, the site of the internal capsule is a good place to occur. The internal capsule is the site through which the nerve fibers connecting the cerebral cortex to the brainstem spinal cord pass, and is located in the basal ganglia region. When the middle cerebral artery supplying the internal capsule is infarcted or the bean artery ruptures and hemorrhages, the patient presents with loss of contralateral hemiplegia, contralateral hemiparesis, and contralateral hemianopsia. As the posterior branch of the internal capsule has motor and sensory nerve fibers and audio-visual radiation fibers passing through it. The perceived external stimuli and various commands from the cerebral cortex pass through the internal capsule. Therefore, the blood supply of the internal capsule mainly comes from the middle cerebral artery of the bean artery.