In an information regenerating apparatus, recorded data constructed of a sector mark and a following header section having a plurality of data sets each having a pull-in pattern, an address mark and address information, is read out to form a regenerative signal which in turn is used to regenerate information. A phase-locked loop circuit in a signal synchronizing circuit, performs phase-synchronization with a regenerative signal at two different pull-in speeds. A speed indicating circuit, based on the counting of the number of clock pulses from a reference clock signal from a time of the generation of a sector mark detection signal showing the detection of the sector mark as a reference point, instructs the phase-locked loop circuit to set up a fast response speed every time the pull-in pattern appears on the regenerative signal, and instructs the phase-locked loop circuit to set up a slow response speed every time the pull-in pattern disappears from the regenerative signal.