Objective To summarize research status and mechanism about effects of carcinoma-associated fibroblasts (CAFs) on breast cancer stem cells. Method Relevant literatures about the relationship between the CAFs and breast cancer stem cells were collected and reviewed. Results CAFs were the majority type of the breast cancer stromal cells. The cancer stromal cell was also the important part of the tumor microenvironment, which could promote the proliferation, adhesion, invasion, and metastasis of the breast cancer. A subpopulation of cancer stem cells with the potentials of self-renewal and multi-directional differentiation in the breast cancer tissues might cause the tumor development. There was a phenotypic heterogeneity in the beast cancer stem cells, it was related to the tumor recurrence and therapy resistance. The CAFs could promote the formation of breast cancer stem cells through the epithelial mesenchymal transition and promote the transformation of tumor stem cell phenotype. More research needed to be done to prove these processes. Conclusion CAFs play an important role in formation of breast cancer stem cells and transformation of tumor stem cell phenotype, which might provide a new idea about treating breast cancer.