To provide a reversible color forming compsn. and a reversible thermal recording medium holding stable color forming properties and color erasing properties and capable of corresponding to a wide range use condition and a wide range environmental condition.

This reversible thermal recording medium is constituted by providing a recording layer containing an electron donating color forming compd. and an electron acceptive compd. as main components and capable of relatively forming a developed color state and an erased color state by the difference of heating temp. and/or a cooling speed after heating on a support. In this case, an ultraviolet curable resin is added to the recording layer to be cured by ultraviolet rays or an electron beam curable resin is added thereto to be cured by electron beam.