In a data recording apparatus, a relative speed of a magnetic head 4 to a magnetic recording medium 5 is changed according to data rates of information data, on recording the information data on the magnetic recording medium by the magnetic head so that said information data is recorded with identical magnetized patterns on the magnetic recording medium even with different data rates of the information data. A control means generates a control signal (SRT) according to the data rates of the information data and a frequency characteristic processing means (12, 13; 22, 23) processes the information data to cause the frequency characteristic of the information data to have a frequency characteristic predetermined according to the control signal. Thereby magnetized patterns on the magnetic recording medium are identical with any data rates and this enables compatibility of record and production of the information data to be kept between different data rates.