A control system for a dot printer having a printing head mounting at least two printing elements thereon per row along a moving direction of the printing head. The printing elements are selectively driven according to a moving position of the printing head to print a dot at a desired column position on a printing paper. The control system comprises a grouping means for grouping dot data to be printed into two groups, wherein the grouping means first groups into one of the two groups the dot data to be printed at column positions spaced a distance equal to or greater than a moving distance of the printing head during a period when the same printing element can be driven, and secondly groups into the other group the remaining dot data not grouped in the first grouping step; and a driving means for driving the printing element assignable to each group on the basis of the data grouped to each group. The dots are assigned independently of what column they are in.