Decursin, isolated from the roots of danggui (Angelicae gigas), has been showed many physiological effects. However, the effects of decursin on cardiovascular diseases such as atherosclerosis were not elucidated. Treatment with a low concentration of decursin ($10-20{mu}M$) showed a significant decrease in invasion and migration by matrigel invasion assay and wound-healing analysis in tumor necrosis factor-${alpha}$ (TNF-${alpha}$)-treated vascular smooth muscle cells (VSMC). MTT assay, however, showed no effect on cell viability. Addition of decursin in TNF-${alpha}$-induced VSMC in zymograhic and immunoblot experiments showed strong inhibition of both matrix metallopeptidase-9 (MMP-9) expression and activation of TNF-${alpha}$-induced transcriptional MMP-9 promoter, which was mediated by suppression of nuclear factor-${kappa}B$ (NF-${kappa}B$) and activator protein-1 (AP-1) binding activities. These results demonstrate that decursin suppresses invasion and migration by inhibition of MMP-9 expression via reducing the binding activities of NF-${kappa}B$ and AP-1 in TNF-${alpha}$-treated VSMC.