Curcumin (1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione), is extracted from the plant Curcuma longa. It was recently reported for its anticancer effect on several types of cancer cells in vitro however, the molecular mechanisms of this anticancer effect are not fully understood. In the present study, we evaluated the effects of curcumin on human mammary epithelial carcinoma MCF-7 cells. Cells were treated with curcumin and examined for cell viability by MTT assay. The cells invasion was demonstrated by transwell assay. The binding activity of NF-κB to DNA was examined in nuclear extracts using Trans-AM NF-κB ELISA kit. Western blot was performed to detect the effect of curcumin on the expression of uPA. Our results showed that curcumin dose-dependently inhibited (P < 0.05) the proliferation of MCF-7 cells. Meanwhile, the adhesion and invasion ability of MCF-7 cells were sharply inhibited when treated with different concentrations of curcumin. Curcumin also significantly decreased (P < 0.05) the expression of uPA and NF-κB DNA binding activity, respectively. It is concluded that curcumin inhibits the adhesion and invasion of MCF-7 cells through down-regulating the protein expression of uPA via of NF-κB activation. Accordingly, the therapeutic potential of curcumin for breast cancer deserves further study.