A stabilizing assembly includes a retaining device settled between a drawable carrier and a cabinet body for preventing the drawable carrier from swinging in sliding. The retaining device includes two rails fixed to two opposite laterals of the drawable carrier. Each of the rails has a rack. Two gears engaging with the racks are connected by a rod and rotate simultaneously. Two bushes connected to two ends of the rod are received in supporting seats that are fixed on the cabinet body or the drawable carrier and allowed to shift vertically. Two stop portions, as a stop unit, each extending from the rail toward a side of the rod opposite to another side of the rod facing the rack on the rail, are closely adjacent to the retained portions so that the bushes are retained and stopped by the stop unit, and disengagement between the racks and the gears is prevented.