Abstract: Objective To improve the rat model of suture occlusion of local cerebral ischemia. Method The right common carotid artery (CCA) and external carotid artery (ECA) were isolated afler anesthesia, We turned the rat head 45° from the middle line to the left, make ECA parallel to ICA and then inserted a thread with an enlarged tip 0.3 mm in diameter and 3 mm in length at the point 18 mm to the bifurcation of ECA and ICA. After 2 h the rats were assessed for neurological evaluation. 20h after MCAO，the rats were sacrificed for TTC stain, the volume was calculated. Result Neurological scoring of each model was 2 point. On TTC staining manifestations of cerebral infarction were found in all rats，and the volume of infarction was about(19.066±1.556)%，the brain volume ratio was about 1.031 ±0.024. The success rate was 93.75%, the mortality is 6.25% and the complication rate is 6.25%. Conclusion The model has shown to be easy to be performed and with high success rate so it is a useful animal model.

Key words: Rat, Permanent middle cerebral artery occlusion, Animal model, Improvement