Abstract: A suitcase structure includes a shell which is reinforced by a reinforcing frame. The reinforcing frame is formed of a bottom tray, a top plate, a back plate, and two side plates. The top plate and the back plate are made integrally. The bottom tray is formed of a bottom rib, a plurality of peripheral ribs raised from the fringes of the bottom rib, and a plurality of reinforcing ribs for reinforcing corners of the peripheral ribs.