A method of controlling a write operation for a rotating type recording medium in which a plurality of tracks are formed in such a manner that each track is divided into a plurality of blocks having respective addresses and each block is used as the information recording/reproducing unit, is disclosed. In this method, each block includes an information recording field and a flag field for indicating the presence or absence of recorded information in the information recording field, to follow the following procedure. That is, when a high-ranking apparatus specifies a block and issues a write instruction for writing information in the specified block, the flag field of the specified block is first checked, and then the first recording mode for immediately recording new information in the information recording field of the specified block or the second recording mode for recording new information in the information recording field of the specified block after an erasing operation has been performed for the above information recording field, is executed depending upon whether the flag field of the specified block indicates the absence of recorded information or the presence of recorded information.