The epithelial-mesenchymal transition (EMT) is characterized by absence of epithelial phenotype and acquiring of mesenchymal properties. EMT participates not only in normal embryonic development,wound healing and tissue reconstruction,but also in various pathologic processes,including fibrosis and carcinogenesis. EMT can facilitate the invasion and metastasis of cancer cells to distant tissues,and confer the metastatic cancer cells self-renewal ability of stem cells,contributing to macroscopical metastasis formation and multiple resistance to treatment. Recent studies have revealed that several transcription factors,signaling pathways,microRNAs and microenvironment components are involved in this process. Here we summarize the recent progress on the roles of EMT and cancer stem cells in tumor metastasis,hoping to provide new insights in target therapy of tumor metastasis and recurrence.