Abstract: The purpose of the experiment is to explore and establish a stable animal model of focal ischemic stroke in which the operation approach technique is accessible,the result is reliable and it has a high reproducibility.34 Sprague-Dawley rats were totally used in the experiment.The rat neurologic deficit and ischemic cortical lesion caused by occluding major middle cerebral artery were studied.The operation was performed under anaesthesia through a small subtemporal craniectomy by using microsurgical techniques.After 24h of occlusion, 27 out of expertmental rats had different grade neurologic deficit.Carbon black studies demonstrated that there were not vessel or had a rare vessel distribution in most part of left corte and basal ganglia.The ischemic area in rat brain was correspond to the grade of neurologic deficit in each animal.Neuropathological studies showed that there was a typical ischemic brain damage in the left cortex and basal ganglia.The experiml ntal animal model is useful for studying the mechanism of acute ischemic stroke.

Key words: rat, middle cerebral artery, occlusion, stroke