Building block collecting box base seat and upper cover

The utility model relates to a chassis and a top cover of a case of blocks taking-in, wherein the chassis comprises a bottom board, two first side boards and two second side boards. The two first side-boards are connected with the two opposite sides of the bottom board, wherein opposite folding lines are arranged on the central line, and further extend towards outer margin to be jointed to the upper of the bottom board, and enables the two lateral margin bottom boards of the upper bottom board to be retracted. Besides, the two lateral margins of the first side boards are connected with alar plates capable of being inwards-folded in perpendicular, and necks are formed at the bottom margin of the alar plates. The two second side boards are connected on the other two opposite sides of the bottom board, wherein opposite folding lines are arranged on the central line, and further extend towards outer margin to be jointed to the top pinch plate of the bottom board, and enables the exterior margin of the top pinch plate to be buckled on the lateral margin of the upper bottom board. Besides, the two second side boards are provided with the cramps corresponding to the neck on the bottom margin of the top pinch plate, and a calking groove is formed in the united place between the two second side boards and the bottom board. The top cover is tabling with the chassis, the main structure of the top cover is same with that of the chassis, thereby the calking groove arranged on the chassis need not to be formed. Besides, the dummy sliders are formed in the calking groove corresponding to the chassis on the opposite folding lines of the second side boards. The utility model is strong and firm in structure and capable of being folded into a shape.