Objective To investigate the effects of shear stress on integrin β 1 and F-actin in endothelial cells (EC) co-cultured with vascular smooth muscle cells ( VSMC ) . Methods The double-immuno-fluoro-cytochemistry, laser confocal scanning microscopy and image analysis methods were used in the study. One group of EC was treated with shear stress 2Pa for 1h?6h?12h and 24h. The other group was maintained under static conditions as a control. Results It is showed that integrin β 1 distributed scattering in cytomembrane and stained faintly, and F-actin located in cytoplasm without polarity and stained faintly also showed in the control. After pretreating EC with shear stress for different time ,we found that incresing time exposed to shear stress increased the staining of F-actin and integrin β 1. Integrin β 1 enchanced gradually with a maximum at 12h then decreased and tended to realign in the direction of F-actin. F-actin kept on increasing staining until 24h and tended to polymerize into strong stress fiber around the cell periphery and realign in the direction of flow. Conclusion The results suggested that integrin β 1 as an important adhesion molecular interaction with F-actin may play a key role in the mechanotransduction of co-cultured vascular endothelial cells .