High blood pressure (hypertension) is implicated in the development of atherosclerosis. Blood vessels are constantly subjected to stretch due to blood pressure and changes in stretch usually instigate adaptive vascular remodeling, including abnormal growth and proliferation of vascular smooth muscle cells (VSMCs) as well as extracellular matrix (ECM). In this experiment, we used bovine aortic endothelial cells and smooth muscle cells (EC-SMC) co-cultured ePTFE vascular grafts subjected to normal atmospheric pressure (as a control), and 100 mmHg hydrostatic pressure for 7 d. The increase of cell layer thickness was observed. When measured, the cell layer thickness increased by 116.2%. The increase of collagen (Type Ⅳ)synthesis was also observed in the immunohistochemistry assay. When stained with toluidine blue, the cells showed metachromatic phenomenon.