Aim To investigate the effect of bone marrow mesenchymal stem cells（BMSC）transplantation on injured vessels endothelium repair and vascular restenosis after carotid balloon injury in rabbits. Methods 48 rabbits of carotid artery stenosis model were established and randomly divided into BMSC transplantation group （n24） and control group （n24）. BMSC were cultured in vitro and transfected with recombinant adenovirus-mediated enhanced green fluorescent protein gene. Balloon injured carotid artery of rabbits, meanwhile, BMSC（10⁷/kg）were infused into rabbits injured artery by external carotid artery in BMSC transplantation group, and the same amount of PBS solution were infused into the control group. 1 week after transplantation, BMSC homing were detected by immunohistochemical techniques. 2 weeks after transplantation, the expression of platelet-endothelial cell adhesion molecule（CD31）, α-smooth muscle actin and proliferating cell nuclear antigen（PCNA）were detected by immunohistochemical staining. 4 weeks s after transplantation, the incidences of the vessels stenosis were detected by carotid artery arteriography, the neointimal area and the ratio of the intima/media area were examined by hematoxylin and eosin staining. Results BMSC with GFP homing were detected in injured vessels intima at 1 week after BMSC transplantation. CD31 continues to have expression in intima of BMSC transplantation group, while the control group did not express. The expression of PCNA in BMSC transplantation group were decreased significantly compared with control group（23.43%±2.80% vs 50.49%±3.60%，P<0.05）. The expression of SM α-actin in BMSC transplantation group were elevated significantly compared with control group（0.437± 0.049 vs 0.197±0.032， P<0.01）. The neointimal area（0.103±0.022 vs 0.214±0.024，P<0.01）and the ratio of the intima/media area（0.771±0.096 vs 1.646±0.223，P<0.01）were significantly decreased in BMSC transplantation group than control group at 4 week. The incidences of the vessels stenosis were decreased compared with control group（39.64%±2.30% vs 63.31%±2.82%，P<0.05）. Conclusion BMSC transplantation can promote repairing of endothelial and phenotypic transforming of vascular smooth muscle cells after carotid balloon injury in rabbits and inhibits neointima hyperplasia. BMSC transplantation can also reduce the restenosis of injured vessels.