Curcumin has been known for its anti-proliferative and apoptotic effects on several cancer cells. We examined the inhibitory effects of curcumin on cancer cell adhesion, motility, invasion and matrix metalloproteinase-9 (MMP-9) activity in MDA-MB-231 human breast cancer cells. MDA-MB-231 cells were cultured with 0, 5, 10 or $20{mu}M$ of curcumin. Curcumin significantly inhibited the adhesion of cancer cells to the fibronectin at $20{mu}M$ and suppressed the motility and invasion of cancer cells at all concentrations. Also, the MMP-9 activity was inhibited by curcumin, but MMP-9 protein amounts were not affected. Our data indicate that curcumin inhibits motility, invasion and MMP-9 activity of MDA-MB-231 cells. Therefore, curcumin may contribute to the potential beneficial food component to prevent the cancer metastasis in human breast cancer.