A cabin mounting structure is applied to construction machinery in which a cabin for riding a driver is mounted on a vehicle body, the cabin mounting structure including: an up and down directional vibration damping unit for damping up and down directional vibration of the cabin, the up and down directional vibration damping unit being mounted between the cabin and the vehicle body; and a front and rear directional vibration damping unit for damping front and rear directional vibration of the cabin, the front and rear directional vibration damping unit 3 being mounted between the cabin and the vehicle body, wherein the cabin is connected to the vehicle body to be relatively movable in a front and rear direction.