Aim To investigate the effect of endothelin-1(ET-1) on osteopontin expression of rat aortic vascular smooth muscle cell(VSMC). Methods Rat aortic vascular smooth muscle cell were cultured in vitro with DMEM and 10 percent calf plasma.The cell were incubated with different concentration of ET-1 for different hours,then RT-PCR and Western bloting analysis were used to observe the effect of H₂O₂ on osteopontin expression of rat VSMC. Results Different concentration of ET-1 could obviously induce gene expression and protein synthesis of osteopontin,without exhibiting dose-dependent promotion effect.Cell incubated with ET-1 for different hours also obviously induce gene expression and protein synthesis of osteopontin except 6 h,and exhibited time-dependence. Conclusions These results demonstrate that ET-1 could stimulate osteopontin expression of rat VSMC.