An optical disk changer system comprises an optical disk changer including M magazines storing N optical disks (N, M: positive integers), which can insert/draw optical disks in each magazine and manages data on a set of optical disks including one or a plurality of optical disks as a volume having a series of logical address; a volume management means including a management table for managing storage position information of optical disks constituting the volume and an unused optical disk management table for identifying unused magazines storing N unused optical disks; a volume creation information means which receives inputs of the number of optical disks or magazines to create the volume; and a volume creation management means for inquiring of the volume management means the storage position information of X unused optical disks to create a volume including X optical disks when positive integer X is input from the volume creation information input means as the number of the optical disks and inquiring of the volume management means storage position information of N X Z pieces of unused optical disks stored in Z pieces of unused magazines to create a volume including N x Z pieces of optical disks stored in Z pieces of magazines according to the number of unused magazines when positive integer X is input from the volume creation information input means.