In an information signal recording and reproducing apparatus, reproduced data is equalized by an equalizer and a clock signal synchronized in phase with the reproduced data is generated. An equalizing characteristic of the equalizer is controlled according to a difference in frequency between the clock signal and the reproduced data, and a generating operation for the clock signal is controlled according to a phase difference between the clock signal and the reproduced data. The clock signal thus can be stably generated without being affected by variations of temperature and variations due to aging. The equalizer thus has an adequate equalizing characteristic. The apparatus includes a recording mode and a reproduction mode. In the recording mode, a recording clock signal is generated by a clock signal generating circuit and a digital signal is recorded by using the recording clock signal. In the reproduction mode, a reproducing clock signal which is synchronized in phase with a reproduced digital signal is generated by the clock signal generating circuit and the digital signal is reproduced by using the reproducing clock signal.