A system for managing data including at least a randomly accessible recording medium, comprised of a data area in which recordal data is recorded in one or more variable length recording blocks by file and a management data area in which file entries and recording entries for each recording block of the files are recorded, the file entries including name data showing the names of the recordal data recorded in the files and identification data showing the record entries of the first recording blocks in which the recordal data are recorded, the record entries including head position data showing the heads of the recording blocks, link data showing the recording blocks in which continuations of the recordal data are recorded, and recording length data showing the recording lengths of the recording blocks.