A method for counting a number of tracks of an optical disc in an optical disc system. The optical disc system includes an optical pickup, a light source, and a plurality of optical sensors. The method includes emitting a light beam to the optical disc from the light source, detecting light reflected from the optical disc by the optical sensors, and generating a tracking error signal according to detected signals of the optical sensors while the optical pickup moves along a radial direction of the optical disc. The method further includes generating a tracking error zero crossing signal according to the tracking error signal, generating a peak detecting signal according to the tracking error signal, generating a pseudo radio frequency zero crossing signal according to the peak detecting signal, and generating a track count signal according to the pseudo frequency crossing signal.