Abstract: A packing box of a portable device is provided, which includes a main plate body and a frame plate body. Plates, which are adjacent to the main plate body and the frame plate body, are respectively disposed with fold-lines; such that a first side plate of the main plate body overlaps a first bonding plate and a third side plate overlaps a second bonding plate to form an accommodating space.: first frame plate, a second frame plate and a third frame plate of the frame plate body are overlapped with one another, so that the first frame plate, the second fame plate and the third frame plate, which are overlapped with one another, separate the accommodating space through a third bounding plate of the frame plate body. When the main plate body and the frame plate body are flattened, the plates are parallel to one another and flat-shaped.