Objective To construct small-sized tissue-engineered blood vessels with hBMSCs(human Bone Marrow Stromal Stem Cells)in our improved bioreactor system.Methods A set of bioreactor system was designed with the application of Finite Element Methods as an analysis method to construct tissue engineered blood vessels with the diameter of 2mm.hBMSCs were first collected and further cultivated.The third passage of the cultivated cells were then seeded on the polyglycolic acid(PGA)to fabricate the cell-scaffold compound.This compound was subsequently subjected to dynamical culturing in the blood vessel bioreactor.Results Tissue-engineered blood vessels can be constructed by culturing the hBMSCs-PGA compound under a dynamic condition.After 4 weeks,the tissues were removed from the bioreactor and subjected to analysis by visual observation,HE,SEM(scanning electron microscope) and immunohistochemistry for smooth muscleα-Actin.It was observed that the tissue-engineered blood vessel appeared bright color and has certain elasticity.The secreted collagen matrix arrayed orderly around the cells and smooth muscle elastic actin can also be detected in the formed tissues.Conclusion The in vivo biological conditions of blood vessels can be simulated using the current blood vessel bioreactor system.Using hBMSCs,the construction of the tissue engineered small-sized blood vessels can be successfully achieved in our bioreactor system.