PURPOSE: To perform at least the quadruple recording with high density by setting the least recording pit length of a recording pattern at or less than 1/4 diameter of a beam spot.

CONSTITUTION: When the record signals 2, 1, -1 and -2 are recorded, a magneto-optical recording medium is irradiated by a laser beam of necessary and sufficient intensity PW. At the same time, a modulated magnetic field HW is impressed to the part irradiated by the laser beam. Under such conditions, the drive current used for generation of the field HW is turned into a modulated current waveform so that each record pit string is recorded. Therefore the modulated magnetic fields of different directions are impressed to the part of the recording medium to be irradiated by the laser beam in accordance with the pit pattern to be recorded with necessary and sufficient field intensity HV. In such a way, the information is recorded. Thus the quadruple optical signal levels 2, 1, -1 and -2 are obtained when the record pit strings 1111, 0110 and 0000 having the smallest record pit length set at or less than 1/4 diameter of a beam spot are recorded on the recording medium.