A slide rail includes a first slide, a second slide, and a third slide, each of the first slide, the second slide, and the third slide comprising a pair of sidewalls. The first slide further includes a bottom wall, the pair of the sidewalls are extended from two edges of the bottom wall respectively. The second slide is received in a space bounded by the bottom wall and the sidewalls of the first slide; the sidewalls of the second slide extend out from the space to contact the sidewalls of the third slide.