PROBLEM TO BE SOLVED : To enforce and facilitate the management of registration-related documents for real estate and registration identification information most important for the right, in managing the documents.SOLUTION : A method for the management of registration-related documents with registration identification information on real estate, which uses a registration-related document, an IC tag or the like, an IC card, a reader/writer for the IC tag or the like and/or for the IC card, and a central processing unit, a file system, a main memory, a program in the main memory and an input/output device all constituting a computer, comprises the steps of attaching one IC tag or the like to each registration-related document, recording necessary data, such as encrypted data on registration identification information and data specifying persons allowed to decrypt the data and view the registration identification information, on the IC tag or the like, and recording data on the registration-related document in a data file in the file system.