Cancer stem cells are the cellular sources of the vast majority of mature cancer cells and are reportedly responsible for the recurrence of disease following anti-cancer therapy. Recent advantages in the cancer stem cell research field have indicated that TGF-β signaling pathway plays an essential role for the maintenance of cancer stem cells via regulating cancer stemness, quiescence, epithelial -mesenchymal transition (EMT), or therapeutic resistance in vivo. Therefore, the outcome of these investigations will hopefully be the development of novel agents that can specifically control both augmentation and suppression of TGF-β signaling pathway in cancer stem cells, and thereby provide a novel avenue for curative cancer patient therapy.