Objective To create a new animal model for exploring restenosis after percutaneous stransluminal coronary angioplasty(PTCA).Method 24 male Sprague-Dawley big rats were randomly divided into 4 groups(n=6).The 2.0F balloon catheter injury was perfomed through the right femoral artery into the left common carotid artery of rats.Around 6 rats from each group were euthanized by exsanguination at appropriate time point.The injuried left common carotid arteries were carefully removed and harvested,then the pathological slides were prepared and stained for optical microscopic observation.Microscopic analyses and quantitation of morphologic parameters were performed using HMIAS-2000,which was a full-automatic computerized colorful imaging analysis system.Results The proliferation of vascular smooth muscle cells(VSMC) was spotted on the surface of vascular lumen at 5d after the rat underwent balloon-dilation injury of the left carotid artery.Artery intimal proliferation progressed gradually as time went on.28days after the operation,morphological analysis demonstrated that there were markedly differences in the area of neointima hyperplasia,the vascular wall collagen proliferation between all model groups and the sham-operated group.Conclusion This experiment successfully duplicated the clinical animal model of RS,the model method of vascular restenosis established by balloon injury of rat carotid artery had the worthy of expansion.