In a method and an apparatus of controlling the movement of a printing head in a printer for printing characters along a print pass while selectively reversing the moving direction of the printing head, in which the character heights of a plurality of character series are checked, image data of a plurality of lines are read out, the image data being contained in a pass which can be printed within the height of the printing head, are printed at once. It is then checked whether or not the printed image data is continuous to the image data of the next pass, the same moving direction of the printing head is kept for printing the image of the next pass if it is continuous, and the moving direction of the printing head is reversed for printing the image of the next pass if it is not continuous. The method and the apparatus can print characters in excess of the height of the printing head with a high quality.