To provide a ribbon winding device for a thermal transfer printer which controls a winding speed according to change of a diameter of a roll along with winding of an ink ribbon R and prevents problems such as shift or expansion in printing and occurrence of creasing of the ink ribbon R.

The winding speed of the ink ribbon R is controlled by using a stepless speed changing type V belt 26, a variable pulleys 24, 25, and the like. The ribbon winding device comprises a ribbon supply section 4 and a ribbon winding section 5 having a winding shaft 10 for winding the ink ribbon R in a roll. A winding speed control mechanism 22 for changing the winding speed of the ink ribbon R by means of the winding shaft 10 according to the diameters of the ink ribbon R on the supply shaft 9 and the winding shaft 10 is provided to a portion between a driving shaft 23 of the driving motor 8 and the winding shaft 10.