To provide a folding packaging box in which materials are saved and assembling the box is facilitated.

In the box which comprises a bottom board, both side walls and front and back walls and in which a lid and grips are hooked and fixed by inserting and hooking hooking boards each with a hooking hole stood from the side walls into uneven hooking parts formed on both sides of a grip under an assembled condition, flap pieces piled up on left and right side walls under a standing-up condition are foldably continuously provided on at least side ends of the front wall or the back wall and the hooking boards are projected and provided on the upper ends of the flap pieces and at lower positions from the top ends of the left and right side walls, channel holes in the left and right direction through which the hooking boards are passed and hooked under a standing condition of the flap pieces are cut through.