Abstract: When user data is recorded on a write-once medium, linking variations can be reduced that are produced as management information for managing the user data is updated by additionally recording on and off, thereby assuring the reliability of the reproduction compatibility of the DVD player. Before the final file of the management information is recorded, dummy data of a plurality of successive blocks are recorded at a time by a single operation, and then the final file is additionally recorded after the dummy data. Therefore, the linking precision can be prevented from being degraded in the linking portions of the management information, and thus the management information can be properly read when the DVD player makes compatible reproduction of the medium.