An object of the present invention is to make it possible to record information on an optical information recording medium in the form of three dimensional interference patterns so that the information is erasable in part.The optical information recording medium (1) has an information recording layer (3) made of a magneto-optic recording material. A pick-up (11) of an optical information recording/reproducing apparatus generates information light by spatially modulating laser light emitted from a light source unit (20) with a spatial light modulator (22), and generates recording-specific reference light spatially modulated in phase by spatially modulating the phase of the laser light emitted from the light source (20) with a phase-spatial light modulator (16). The information recording layer (3) of the optical information recording medium (1) is irradiated with the information light and the recording-specific reference light. An electromagnetic coil (30) applies a magnetic field to the information recording layer (3). A three-dimensional distribution pattern of magnetization corresponding to the interference pattern resulting from the information light and the recording-specific reference light is formed in the information recording layer (3).