The aim of our study was to gain insight into the molecular and cellular mechanisms of post-angioplasty restenosis using balloon catheter-induced injury model in the rat carotid artery. SD rats were subjected balloon catheterization at one side carotid artery as study group and another side as control group. Six rats were killed on the 6 h, and 3rd, 7th, 14th, 28th day after balloon-induced injury respectively. The intimal thickness and the expression of NF-кB and I-кB were detected by HE-staining, gel electrophoretic mobility shift assay (EMSA) and Western-blot methods. The results showed that: (1) The thickening of intima was observed on the 3rd day after balloon-induced injury,and it became more significant on the 7th, 14th and 28th day. The area ratio of intima/media was in-creased significantly (P＜0.05); (2) The expression of NF-кB was not detectable in the control group,however, in study group, the expression of NF-кB was detected on the 6th h after balloon-induced injury, reached the peak on the 14th day, and on 28th day, strong expression of NF-кB was observed;(3) The expression of I-кB protein was reduced after balloon-induced injury, and there were signifi-cant differences between the study group and the control group (P＜0.05). It was concluded that the alteration of NF-кB/I-кB system might play an important role in aberrant proliferation within the in-tima and vascular remodeling following vascular injury. To block NF-кB activation and its role in ar-terial restenosis initiation may potentially provide a novel therapeutic tool for the treatment and pre- vention of arterial restenosis.