The　retinal　image　registration　has　important　applications　in　the　processes　of　auxiliary　diagnosis　and　treatment　for　a　variety　of　diseases.　The　retinal　image　registration　can　be　used　to　measure　the　disease　process　and　the　therapeutic　effect.　A　variety　of　retinal　image　registration　techniques　have　been　studied　extensively　in　recent　years.　However,　there　are　still　many　problems　existing　and　there　are　numerous　research　possibilities.　Based　on　extensive　investigation　of　existing　literatures,　the　present　paper　analyzes　the　feature　of　retinal　image　and　current　challenges　of　retinal　image　registration,　and　reviews　the　transformation　models　of　the　retinal　image　registration　technology　and　the　main　research　algorithms　in　current　retinal　image　registration,　and　analyzes　the　advantages　and　disadvantages　of　various　types　of　algorithms.　Some　research　challenges　and　future　developing　trends　are　also　discussed.