A bush and a bearing structure is provided wherein the bush slides along a guiding rod, and the bush is a circular body with an opening to cover the guiding rod over a semicircle. An included angle between the opening and the center of circle of the guiding rod is less than 180 degrees for installing the bush into the bearing structure of a sliding device. The bush is a guiding interface for guiding the sliding device sliding along the guiding rod, and the sliding device can slide along the guiding rod stably.