A disc playback system according to this invention, as shown in FIG. 1, comprises a pickup 1 for reading information from an information disc 2 on which data are recorded at a constant linear velocity, a disc motor 16 for rotating the information disc 2, a digital signal processing means 7 for digitizing data according to the playback format of the information disc 2, an interface means 19 for transmitting the digitized data to an external device and a buffer memory 18 for temporarily containing the data, and further includes a means for detecting the linear velocity and track pitch of the information disc 2 to decide the reference value for the velocity control of the disc motor 16 on the basis of the detected values of the linear velocity and track pitch and the value of the maximum radius of the data record area. According to the so-constructed disc playback system, the maximum playback velocity of the system can be obtained even in the case of discs having different track pitches.