PURPOSE: To enhance water resistance, plasticizer resistance and oil resistance, in a thermal recording material wherein a thermal color forming layer and a protective layer are formed on a support, by adding carboxyl modified polyvinyl alcohol, an aldehyde compd. and a polyamide epoxy resin to the protective layer.

CONSTITUTION: In a thermal recording material constituted so that the thermal color forming layer formed on a support is heated by a thermal head or laser beam to instantaneously react a color former in the color forming layer to form a recording image and a protective layer is provided on the thermal color forming layer, as the component constituting the protective layer, a crosslinking agent selected from carboxy modified polyvinyl alcohol, an aldehyde compd. and a polyamide epoxy resin is added. At this time, glyoxal is pref. used as the aldehyde compd. and polyamide epichlorohydrin is used as the polyamide epoxy resin. By this constitution, glyoxal generates intermolecular crosslinking to develop water resistance.