Abstract: A thermal transfer recording medium such as a color thermal transfer paper or ribbon which is used in combination with a thermal head or pen to print an image on an image forming body or sheet. The thermal transfer recording medium comprises a polyester supporting film, a first thermal transfer layer formed on the supporting film, which consists mainly of a saturated polyester copolymer having a molecular weight of 8,000 to 30,000 and containing a sublimation or hot-melt transfer dye. A second thermal transfer layer containing a dye as that of the first transfer layer may be formed on the first transfer layer. The thermal transfer image forming body comprises a supporting body, a dyeing image forming layer formed on the supporting body and made mainly of a thermoplastic resin having four or more OH group per molecule, a tensile break strength of 300 kg/cm.sup.2 or more and tensile break elongation of 20% or more, and a surface layer made of a silicone resin.