Packaging box

A packaging box includes a box body and at least one foldable plate. The box body includes a loading plate and a plurality of side plates. The loading plate has at least one opening and two first edges located at the opening. The two first edges face towards each other. There is a plurality of distances having different lengths located between of the two first edges. The side plates surround the loading plate to form a first accommodation space. The foldable plate is connected to the loading plate to have a lying position and a standing position. The foldable plate includes a plurality of interposing parts having different widths, and a width of one of the interposing parts is greater than a length of one of the distances located between the two first edges. The foldable plate covers the opening when located at the lying position. When the foldable plate is located at the standing position, the foldable plate folds relative to the loading plate to interpose the interposing part between the two first edges; th