The most serious problem facing the implantation of vascular graft in the body is the formation of blood clots. In order to solve this problem, various attempts have been made by the scientific community for many years. However, endothelialization is the fundamental method to solve thrombosis and keep vascular graft open for a long time. Poly （ε-caprolactone） (PCL) has the advantages of biodegradability, low cost and good mechanical properties. In recent years, it has been widely used as tissue engineering scaffolds, drug deliverys and so on. This article mainly reviews the endothelialization of small-caliber vascular graft based on PCL after implanted in different animal models, as well as the endothelialization of the same animal model but under different implantation conditions, and trying to find the reasons why small-caliber vascular grafts are still not ideal in clinical applications at different angles such as the different animal models and the different way about endothelialization, and provide references for future animal model selection.