To provide a thermal transfer sheet having a back layer excellent in heat
resistance and slipping properties and causing no wrinkling at printing
and no image-defect by tailing, the sheet being able to be prepared
without a heat treating, such as aging.A thermal transfer sheet,
comprising a substrate film, a transfer ink layer formed on one face
thereof, and a back layer formed on the other face thereof, wherein the
back layer comprises: a mixed binder containing a polyamide-imide resin
(A) having a Tg of 200.degree. C. or higher as determined by differential
thermal analysis and a polyamide-imide silicone resin (B) having a Tg of
200.degree. C. or higher; a mixture of a polyvalent metal salt of
alkylphosphoric ester (C) and a metal salt of alkylcarboxylic acid (D), a
silicone oil (E); and an inorganic filler (F).