Abstract: The disadvantages of conventional carton for packaging cut sheets of paper such as the facts that fingers or finger nails are injured upon opening the carton, tearing requires a large force, the removal of the cut sheets is difficult, the beauty of surroundings is spoiled, movement of the carton is required, and industrial wastes are produced are solved by the present invention. A pair of opening face cut lines such as threaded lines, zipper and the like are formed on two selected faces of the rectangular parellelepiped carton, and a trigger cut line such as a threaded line, zipper and the like is formed on this one face or another face. The trigger cut line is connected to the opening face cut lines. The trigger cut line and the opening face cut lines are torn off after cutting and raising a part of the trigger cut line. The face having the opening face cut lines is used as an opened face.