As an importantmetal ion chelator, ethylenediamin- etetraacetic acid(EDTA)has been widely used in many fields of industrial, medical and biological engineering and so on. There were reports about EDTA being used to treat band keratopathy and some other ophthalmic diseases as early as the mid-20^th century. And in the subsequent studies, researchers had discovered that the EDTA is a good penetration enhancer which can release the tight junctions between the corneal epithelial cells, and indirectly increase the transshipment of drugs to the cornea. Recently, the chelating function of EDTA has also been widely used for separating or extracting of corneal cells in biological engineering. The purpose of this paper is to review the applications of EDTA's chelation in the treatment of corneal diseases, the penetration of ophthalmic agents to cornea and the corneal biological engineering.