The biocompatibility of the NiTi alloy self-expanding stent, its dilating effect on the vascular wall, and the apoptosis of smooth muscle cells (SMCs) were studied by implantation of stent into the rabbit’s abdominal aorta for different period. All the animals lived throughout the study. There was no detectable migration or dissection of the stent, and there were no acute closures or sub-acute thromboses in the vessels. The rates of patency were 100% both at the beginning when the stent was implanted and at the end when the animal was sacrificed. It may be concluded that the vascular intima covers the whole stent at the 8-week point. The atherosclerotic process existed in the vascular intima in contact with the stent surface, while the proliferation and apoptosis of SMCs occured simultaneously. After stent implantation, the apoptosis happened in both intima and media, which indicated that the stent might not only stimulate the intima but also compress the media, leading to proliferation and apoptosis. This might contribute to vessel remodeling after stenting.