An in vitro model was built for researching the effects of strain on vascular smooth muscle cells (VSMCs). The cultured VSMCs was stretched by four-support-bending-beam system, then the project area of cells was measured by computer-image-processing, the adhesion force was measured by micropipette-aspirating system, the α-actin of VSMCs was distinguished by immunocytochemistry and the dynamic of VSMCs was determined by FCM. The results show that: (1) The adhesion force of VSMCs is positively related to time. The adhesion force of unit area is indistinct after stretched for four hour. (2) The amount of α-actin increases with stretching time. (3) The proliferation of VSMCs is a little inhibited by stretched 24 h. These results suggest that the VSMCs in vitro could adjust their behavious to adapt the tension.