Disclosed is a method to improve iris recognition success ratio and speed by registering the iris code on location of illuminator. In the present invention, iris codes for a single iris generated as many as the number of a plurality of illuminators are registered on an iris database every area corresponding to the location of the illuminator. The iris codes generated one by one whenever the plurality of illuminators are turned on one by one for recognition are searched on the corresponding areas of the iris database to determine the recognition.