Aim To elucidate the effect of estradiol on the endothelium of rabbits iliac artery after balloon injury. Methods 28 female rabbits were randomly divided into four groups. All rabbits were ovariectomized. The endothelial denudation was performed by utilizing the balloon of percutaneous transluminal coronary angioplasty in rabbit right iliac artety. 2 weeks and 4 weeks after balloon injury of the artery, serum levels of estradiol were measured and reendotheliums were assessed by IBAS 2000 morphometric system. The functions of endothelium were tested by measuring the nitric oxide (NO) levels of injured artery. Results Serum levels of estradiol significantly elevated in estrogen treated groups compared with the control groups(p<0.01). The reendothelialization was more accelerated in estrogen treated groups(p<0.05), the corelationship between them is strikingly. The enhanced NO release were observed in estrogen treated groups(p<0.05). Conclusions Estrogen can accelerate reendothelialization after balloon injury and protect the function of injured vascular endothelial cells, so as to have the effects of antiatherosclerosis.