The present invention relates to a method for converting mesenchymal stem cells into endothelial cells by using specific transcription factors and, more specifically, a method for converting mesenchymal stem cells into endothelial cells by using Oct4, Nanog, Tal1, and LMO2, which are specific transcription factors. According to the present invention, the method for converting adult cells or mesenchymal stem cells, which are adult stem cells, into endothelial cells was developed by selecting two types of genes, which are less directly related to cancer induction, among cell reprogramming factors and two types of transcription factors, which are not expressed or expressed at a low level in mesenchymal stem cells, among transcription factors related to vascular development, and combining all four transcription factors. The method can be applied in the production of endothelial cells for forming regenerative tissue in tissue engineering and ischemic disease therapy.