To obtain an information recording card which makes the rewriting of information difficult and is excellent in prevention of forgery by providing this card with a recording layer contg. polymer hollow particulates and irreversibly changing the reflectivity thereof by heating or pressurizing.

The polymer particles are heated or pressurized by utilizing the higher refractive index of the polymer than the refractive index of the air in the polymer hollow particulates and the reflection of light at their boundary, by which the particles are deformed and the reflectivity is lowered. A coating material prepd. by dispersing the polymer hollow particulates and a binder into a solvent is applied on a substrate 2 and is dried to form the recording layer 3, by which the information recording card 1 is obtd. The information recording card 1 is passed in a reader-writer provided with a thermal head and a photosensor. Writing of the information is executed by heating the prescribed parts in the coating film according to the use frequencies of the information recording card 1, thereby lowering the reflectivity. The temp. of the thermal head is raised to plasticize or melt the polymer particles. The polymer hollow particulates consist of a styrene system, acrylic system, etc.