An editing system includes an editing device 1 for editing a plurality of channels of video data, a disk recorder 2 constituted by a disk array having a plurality of disks, and a computer 3. The disk recorder 2 prepares a block map for managing recording areas on the disks so that respective subblock data are recorded at such position that a rotational delay time of a head becomes minimum in accessing the subblock data recorded on the respective disks. The disk recorder 2 then divides pixel data of source video frames into a plurality of subblocks for each frame on the basis of the block map, and records the subblocks so that the subblocks are dispersed on a plurality of different disks.