Abstract: Abstract　The cancer stem cell hypothesis suggests that tumors originate from the abnormal proliferation and differentiation of cancer stem cells. Conventional therapies, such as radiotherapy and chemotherapy, only kill the non-tumorigenic tumor cells at the proliferative phase, resulting in the minification or even the disappearance of tumors. However, like normal stem cells, tumor stem cells are highly resistance to radio-chemotherapy, and they may proliferate again to develop the tumor upon cessation of treatment. Cancer stem cells are present in breast cancer and play a key role in the carcinogenesis and progression of breast cancer. They not only mediate resistance to chemotherapy and radiotherapy of the breast cancer, but also correlate with metastasis and the recurrence of cancer. Therefore, extensive studies on breast cancer stem cells are needed. The current study summarizes the progress in the isolation and identification of signal pathways and related therapies related to breast cancer stem cells.