Abstract: An improved structure of linear sliding rail circulating device is primarily composed of: a rail, which laterally forms a sliding path; a sliding base, which slides to operate along said rail, and is provided with an aperture at the interior for receiving the rolling elements; and combination ends, which are circulating system correspondingly formed subject to the H-shape or U-shape rail for connecting to the front and rear ends of the sliding base to serve as closes of the rolling path of the rolling elements and U turns for the rolling elements. Accordingly, rails of various types can be partially altered common components, thereby easing device maintenance and minimizing manufacture costs.