To provide a thermosensitive recording medium, which is highly sesntive and excellent in heat resistance, light resistance and water resistance.

In the thermosensitive recording medium, the support of which is overlaid with a thermosensitive recording layer including a colorless or light-colored basic dye, a developer, which colors in reaction with the dye and an intensifier, 3-dimethylamino-7-(m-trifluoromethylamino)fluoran is included as the dye, 2,4'-dihydroxydiphenylsulfone is included as the developer, 2-(2'-hydroxy-5'-methylphenyl)benzotriazol is included as the intensifier and, in addition, 1,1,3-tris(5-chlorohexyl-4-hydroxy-2-methylphenyl)butane is included.