A cart includes a first side board and a second side board. Each of the first and second side boards has first holes and second holes respectively defined in the upper and lower portions thereof A first rod unit and a second rod unit are respectively connected to the first holes and the second holes of the first and second side boards. At least two shelves are movably mounted on the first and second rod units between the first and second side boards. A first wheel unit and a second wheel unit are respectively connected to the second holes at the front side and the rear side of the body so as to assemble the cart. The diameter of the second wheel unit is larger than that of the first wheel unit. The cart is light and suitable to move on an uneven surface.