All cells in human body receive oxygen and nutrients and remove metabolic wastes through the vascular network. New vessel formation in a human body is significantly decreased in adults compared with fetus. New vessel formation is a critical process in pathogenesis, thus, it is a therapeutic target in several diseases, such as cancer, diabetic retinopathy, myocardial infarction and cerebral ischemia. Angiogenesis initiates through the interaction of several factors. For the increment of angiogenesis, new vessel promoting factors, such as vascular endothelial growth factor, or their genes have been directly injected to patients in the past. However, in recent studies, direct injection of cells promoting blood flow to patients has been attempted. In this paper, I will focus on cell therapy and its application in promoting blood flow in patients with impaired vessel such as myocardial infarction, cerebral ischemia and limb ischemia. (Korean J Med 79:630-634, 2010)