To provide a carton packing machine for selectively manufacturing both of two kinds of cartons juxtaposed along the vertical axis of the cartons.

This multipurpose carton packing machine has a conveyor assembly 13 for a box. A first conveyor 19 forms a sub-group of the box 4 stacked by bringing down by feeding the individual box 4 aligned and continuously arranged on a side surface to a storage part 26. A second conveyor 27 is associated to the first conveyor 19 to feed the box 4 to a packing machine 14 by receiving the box 4 carried by the first conveyor 19. The conveyor assembly 13 takes a first form for receiving a continuous body of the sub-group of the box 4 placed by bringing down from the first conveyor 19 by connecting the second conveyor 27 to the first conveyor 19 by the storage part 26 and a second form for receiving the individual box 4 aligned and continuously arranged on the side surface by connecting the second conveyor 27 to the first conveyor 19 on the upstream side of the storage part 26.