Cancer stem cells (CSCs) refer to a subpopulation of tumor cells that have abilities to self-renew, differentiate, and seed new tumors, they might be taking part in tumor-associated angiogenesis via trans-differentiation or forming the capillary-like vascular mimicry (VM) in the tumor microenvironment. CSC-associated tumor neovascularization partially contributes to the failure of cancer treatment. The study of CSCs transdifferentiating to endothelial cells or pericytes can provide a new insight in the understanding of tumor progression and relapse.