To provide a reversible heat-sensitive record displaying medium, which has a favorable image contrast, with which the formation and erase of an image are possible, which is damaged a few even through the repetitive use between coloring and decoloring an which has an excellent durability and a high humidity resistance.

A leuco dye/polymer compound type heat-sensitive recording layer resin is produced by being used for the reversible heat-sensitive record displaying medium by dispersing a leuco dye and a reversible developer in a resin matrix made of an epoxy compound (A) and a polymerizable unsaturated monomer polymer (B) and a reversible heat-sensitive record displaying medium has a reversible heat-sensitive recording layer including the leuco dye and the reversible developer, which colors the leuco dye under heat and then decolors it under re-heat, and the resin matrix.