Disclosed is an origami sheet for making a regular hexahedron box, including: first to fourth main outer wall sections connected successively along a longitudinal central area to be foldable with regard to one another; and first to fourth wing sections connected to both longitudinal sides of the first to fourth main outer wall sections to be foldable, respectively. The first and second wing sections and the third and fourth wing sections are connected to be foldable with regard to each other, and the second and third wing sections abut each other with interposed incision lines.