PURPOSE: To output a clock as art outside clock optimal for reproducing recorded data by sampling the regenerative signals of reference clocks recorded on a recording medium using outside clocks whose phases are different from one another and selecting the outside clock having a phase whose difference in sampling value is in minimum.

CONSTITUTION: This generator is a data reproducing clock generator using the recording medium where the reference clocks are recorded. The generator is provided with an outside clock forming means l for forming plural outside clocks 1 to 7 whose phases are different from one another and an A/D converter 11 being a sampling means for sampling the reproducing signals of the reference clocks using the respective outside clocks 1 to 7 formed by this means 1. It is also provided with an outside clock selecting means constituted of a second selector 18 for detecting the minimum value of the differences in sampling values corresponding to the respective outside clocks 1 to 7 from the converter 11 and outputting it and a system controller 17 for selecting one out of the outside clocks 1 to 7 from the outside clock forming means 1 corresponding to the minimum value detected by this selector 18 and outputting it.