A CLV optical disc capable of recording the information with a constant linear velocity. In the CLV optical disc, plural lines of specified track exist in the predetermined data area, railroad length of the tracks is integer times of the length of a sector, the length of the sector on the specified tracks is 2N times of a track pitch, the number N is a positive integral number, and head positions of the specified tracks are lined up on a predetermined radius line A—A at equal track intervals. Fixed-length track marks are arranged at equal physical length intervals along the information track formed in the state of a spiral. The track position information is obtained by detecting the track marks of the present and adjacent tracks. The CLV optical disc medium recording/reproducing apparatus can perform the seeking operation by use of the CPU and the other relevant units regardless of the operation of controlling the disc revolution number. In the CLV optical disc master board exposure, the CLV drive ordering pulse creating method can be realized by the spindle rotation ordering pulse train and the slider movement ordering pulse train.