Objective To study the mechanism of restenosis following percutaneous transluminal coronary angioplasty(PTCA),and to replicate a dynamic model of cell proliferation and remoulding of vascular wall at different time points in rabbits after intimal injury.Methods The model of restenosis in common carotid artery was established by balloon injury in 70 rabbits.The indexes such as lumen area,thickness and area of intima and media,and cross sectional area bounded by the external elastic lamina(EELA) were respectively measured by computer image analysis technology at the 1st,3rd,5th, 7th,14th,28th and 35th day after the injury.Results Endothelial cells were denudated at the 1st day after injury.The proliferation of vascular smooth muscle cell(VSMC) was detected on the surface of lumen at 3 days after injury.At the 7th day after injury,the neointima was formed and continuously thicken.The thickness and area of the neointima as well as extracellular matrix were gradually increased after 14 days,and were maximal after 35 days.The thickness and area of media were also gradually increased during 3～14 days and decreased after 28 days.Compared with non-injured vessel,the medial area was obviously increased at the 14th day.The lumen area was decreased at the 5th～7th day after injury and was obviously less than that of non~injured vessel after 14 days.The EELA was gradually increased at the 1st～7th day after injury,and reached its maximum at the 14th day.The EELA was declined gradually after 28 days.Conclusion The progress of restenosis(RS) can be simulated through the model of restenosis in common carotid artery of rabbit established by balloon injury.The intimal proliferation and vascular remodeling are the leading pathogenesis of restenosis.