PURPOSE: To provide a structure in which the rotary fulcrum of a dust bin to a cart in dumping can move along with dumping slightly upward in the dumping direction.

CONSTITUTION: In the dust bin dumping structure of a dust cart in which the dust bin 2 inclinably carried on the chassis frame 5 of a cart body is dumped, a bracket 6 is provided projectedly faced downward in the lower face of the dust bin mentioned above, and the upper and lower portions (c) and (d) of this bracket 6 and portions (a) and (b) of the dust bin 2 of the aforementioned chassis frame 5 along the dumping direction are rotatably connected by two links 7 and 8 respectively to constitute a four joint rotary chain structure.