Disclosed are a method for preparing induced pluripotent stem cells from endocardium-derived adult stem cells isolated from peripheral blood and a method for differentiating induced pluripotent stem cells into cardiovascular cells. The endocardium-derived adult stem cells are primary culture cells for preparing induced pluripotent stem cells, can be readily isolated and cultured only with a small amount of peripheral blood, have a high proliferation property so as to be storable without generic variation, and can rapidly ensure a cell number so as to be usable in cell therapy. The endocardium-derived adult stem cells have sternness, thereby having high preparation efficiency, and are derived from the endocardium so as to have the epigenetic memory of cardiovascular cells, thereby having an advantage of being able to be differentiated, after preparing induced pluripotent stem cells, into cardiovascular cells such as endothelial cells, smooth muscle cells and cardiomyocytes with a high efficiency.