PROBLEM TO BE SOLVED : To provide a method and a system for precisely reflecting a real price and requiring very small human labors at the time of update and to provide a computer-readable program in the update of land price information of real estate.SOLUTION : For updating registered land price information on plural places, which are previously stored in a storage means, plural update reference places related to registered land price information are previously decided and registered land price information is updated based on land price fluctuation information which is individually prepared at every update reference place. When land price fluctuation information is individually prepared at every update reference place and a method for updating registered land price information is taken based on land price fluctuation information, only the land having high correlation with the fluctuation of registered land price information can be selected as the update reference place. Thus, actual land price fluctuation can highly precisely be reflected at the time of update without tempering the fluctuation of the place which has low correlation or which does not have correlation at the time of update.