PURPOSE:To enable continuous gradation recording of good linearity to used energy and a large dynamic range by executing recording by a difference in the degree of crystallization between a recording part and non-recording part. CONSTITUTION:An 830nm semiconductor 1 is polarized through a polarizing beam splitter 2 and a quarter-wave plate 3 to circular polarized light which is then focused by an objective lens 4 onto a recording medium 5. The recording medium 5 is produced by dissolving a high-polymer liquid crystal expressed by the formula [I] at 10wt.% in cyclohexanone, adding the near IR absorption dye expressed by the formula [II] to the soln., coating such soln. uniformly on a glass substrate 6, and drying the coating to form the high-polymer liquid crystal 7 and further depositing an aluminum reflecting layer 8 by evaporation thereon. The high-polymer liquid crystal 7b is transparent and has about 40% reflectivity ion this state, but the reflectivity changes in approximately proportional to the laser irradiation time when laser light is projected to such liquid crystal. The continuous gradation recording is thereby enabled.