A slide rail assembly, comprising: a first rail comprising an upper wall, a lower wall, and a longitudinal wall connected between the upper wall and the lower wall, the upper wall, the lower wall, and the longitudinal wall defining a channel; a second rail (30, 206) displaceable with respect to the channel of the first rail between a first position, which is a retracted position with respect to the first rail, and a second position, which is an extended position with respect to the first rail; and a reinforcing structure (32, 200) located at the second rail (30, 206); wherein when the second rail (30, 206) is displaced with respect to the first rail from the first position to the second position, the reinforcing structure (32, 200) partially protrudes beyond the first rail in a direction of the displacement of the second rail, wherein the slide rail assembly further includes a bracket device mounted on the first rail and an engaging member arranged on the second rail on the side of the longitudinal wall of the second rail that is adjacent to the first rail, and wherein the bracket device includes a fastening member having a first engaging structure and the engaging member includes at least one second engaging structure corresponding to the at least one first engaging structure; wherein the second rail includes an upper wall, a lower wall, and the longitudinal wall connected between the upper wall and the lower wall; wherein the upper wall and the lower wall of the second rail correspond to the upper wall and the lower wall of the first rail, respectively, wherein the reinforcing structure comprises a sidewall mounted on the longitudinal wall of the second rail characterized in that the reinforcing structure (32, 200) is provided on the side of a longitudinal wall of the second rail (30, 206) that faces away from the first rail, and in that when in the first position, the upper wall of the first rail extends between the upper wall of the second rail and the reinforcing structure, and the lower wall of the first rail extends between the lower wall of the second rail and the reinforcing structure. a first rail comprising an upper wall, a lower wall, and a longitudinal wall connected between the upper wall and the lower wall, the upper wall, the lower wall, and the longitudinal wall defining a channel; a second rail (30, 206) displaceable with respect to the channel of the first rail between a first position, which is a retracted position with respect to the first rail, and a second position, which is an extended position with respect to the first rail; and a reinforcing structure (32, 200) located at the second rail (30, 206); wherein when the second rail (30, 206) is displaced with respect to the first rail from the first position to the second position, the reinforcing structure (32, 200) partially protrudes beyond the first rail in a direction of the displacement of the second rail, wherein the slide rail assembly further includes a bracket device mounted on the first rail and an engaging member arranged on the second rail on the side of the longitudinal wall of the second rail that is adjacent to the first rail, and wherein the bracket device includes a fastening member having a first engaging structure and the engaging member includes at least one second engaging structure corresponding to the at least one first engaging structure; wherein the second rail includes an upper wall, a lower wall, and the longitudinal wall connected between the upper wall and the lower wall; wherein the upper wall and the lower wall of the second rail correspond to the upper wall and the lower wall of the first rail, respectively, wherein the reinforcing structure comprises a sidewall mounted on the longitudinal wall of the second rail characterized in that the reinforcing structure (32, 200) is provided on the side of a longitudinal wall of the second rail (30, 206) that faces away from the first rail, and in that when in the first position, the upper wall of the first rail extends between the upper wall of the second rail and the reinforcing structure, and the lower wall of the first rail extends between the lower wall of the second rail and the reinforcing structure.