The functional realization is the most important problem in vascular tissue engineering. The small-caliber blood vessel substitutes are prone to thrombi, which results in functional loss of blood vessels. However, this is probably due to the imperfection of endothelial layer in the substitutes. In this study, MSCs were seeded on a series of porous PLGA films with various porosity and pore size made by sodium chloride (NaCl) particulate leaching, and cell proliferation on each film was inspected. The film made of the 75% (w/w) particulate proportion and 30―50 μm pore size maximized the proliferation rate and was chosen as the scaffolds for the differentiation of MSCs into endothelial cells. The induced cells expressed endothelial cells specific Flk-1, Ⅷ factor and CD34, possessed endothelial cells specific Weible-palade (W-P) body, and had the abilities of ingesting low density lipoprotein and secreting prostacyclin (PGI2). The results show that MSCs not only have the ideal biological compatibility with the porous PLGA films, but also have the potency of differentiating into functional endothelial cells, which should facilitate the endothelialization in vascular tissue engineering.