The present invention relates to a method for preparing corneal endothelial progenitor cells by adherent culturing a cell population isolated from corneal endothelial cell tissue at a low density by using a serum-free medium. The present invention also relates to a method for preparing corneal endothelial cells by differentiation-inducing the corneal endothelial progenitor cells obtained by the aforementioned method. According to the present invention, corneal endothelial progenitor cells can be selectively grown from a corneal tissue-derived cell population, and corneal endothelial cells obtained by inducing the corneal endothelial progenitor cells can be applied to treatment of corneal endothelial diseases. As a result, problems of corneal transplantation such as shortage of donors and occurrence of rejection can be solved.