Endothelial progenitor cells have great prospect for treatment of many diseases. However, derivation of endothelial progenitor cells in vitro is a major restriction for the clinical treatment. Human embryonic stem cells (hESCs) may become an alternative source of endothelial progenitor cells because of their high proliferation capability and in vitro pluripotency. Although, there are many challenges for differentiating hESCs to endothelial progenitor cells in vitro. Current understanding of this subject from recent discoveries in this field was summarized. Future work will be needed to translate these in vitro findings to clinical applications.