MiRNAs play an important role in regulating tumor migration and invasion, and abnormal expression of miRNAs occurs in various kinds of human cancers. In this essay, it is reported that the level of miRNA-218 decreases in metastatic breast cancer cells, moreover, miRNA-218 suppresses breast cancer cells migration and invasion through binding Robo1 (one of Slit receptors) to its 3'UTR. MiRNA-218 restoration suppresses Robo1 expression and inhibits breast cancer cells invasion and migration. What the results describe is that the function of Robo1 regulated by miRNA-218 may provide a new strategy for inhibiting migration and invasion of breast cancer cells.