Objective In order to solve the scaffold material and the cell source of the tissue engineering bile duct.This experiment was divided into two parts: ⑴To cultivate the vascular smooth muscle cell(VSMCs)in vitro and observe the cultivate status of the VSMCs in 3D environment of polylatic acid-polynlycolic acid(PLGA).⑵To explore the feasibility of differentiation of rat bone marrow stromal cells towards liver stem cells in vitro.Method ⑴To cultivate the VSMCs with PLGA(the film material with 3D material) after they were successfully cultivated,and to observe the cell growth status by inverted microscope,scanning electron microscope and MTT.⑵To culture rBMSCs in vitro by culturing the full bone marrow stem cells in a system containing hepatocte growth factor(HGF).The morphology of the cells was observed by inverted microscope,and the expressions of albumin,AFP were detected with ELISA and immunohistochemistry technique.Result ⑴The VSMCs growth is prosperous in vitro with good compatibility with PLGA.⑵After being cultured with HGF,the rBMSCs showed multilateral and ovary tansformation.The differentiated cells expressed albumin and AFP.Conclusion ⑴The VSMCs were successfully cultivated and purified in vitro and have good compatibility with PLGA.⑵ The rBMSCs have the ability to-differentiate into liver stem cells in vitro.The current studies provide the experimental basis for rBMSCs to differentiate into endothelial cells of the bile duct.