Abstract: To evaluate the value of circulating endothelial cells as the resource of endothelial-ization,by seeding of ePTFE prostheses interposition grafts in dogs, making prepare for endothe-lialization of ePTFE in vivo. Methods：Dog bone marrow monocytes were isolated by centrifugation. The procedure of endothelial lining ePTFE prostheses（4 mm×4 cm and 8 mm×5 cm）were finished and interposed in carotid artery and inferior vena cave in 20 dogs. Doppler ultrasound were performed before animal were killed 2 weeks and 2 months after surgery, and graft segments were grossly evaluated and then under pathological examination, immunocytochemistry ob-servation and scanning electron microscopic analysis. Results：Patency rates for seeded grafts in carotid artery group were 100% （5/5）and 60% （3/5）at 2 week and 2 month respectively, control grafts had a patency rate of 40%（2/5）and 0%（0/5）at corresponding times；Patency rates for seeded grafts in inferior vena cava group were 83. 3%（5/6）and 50% （2/4）at 2 month in experiment grafts and control grafts respectively.Scanning electron microscopy showed endothelial cells coverage rates were different between experiment and control groups at carotid grafts （2 month）（84%±11% vs 43%±15%，P＜0.05），so did at inferior vena cava（95%±6% vs 77%士 13%，P＜0. 05）. Neointimal thickness was thinner in experiment grafts as compared with those of control grafts at 2 month（116±28 μm vs 162±30 μm，P＜0.05； 91±24 vs 143士35 pm， P＜0.05）. Conclusion：Lining ePTFE protheses with bone marrow-derived endothelial cells fa-cililated luminal endothelialization and induced less chronic intimal proliferation；As the potential source，circulating endothelial cell had definite value in the endothelialization of protheses in vivo.

Key words: Endothelial cells, Artificial vessel, Endothelialization, Transplantation