A slide rail assembly for a chassis system, the chassis system comprising a first chassis and a second chassis detachably mounted on the first chassis, the first chassis having an inner space, the first chassis comprising a wall, an opening formed on the wall and communicated with the inner space, the slide rail assembly comprising: a first rail comprising a blocking feature; a second rail movable relative to the first rail along a longitudinal direction, the second rail mounted on the first chassis, a through hole formed on the second rail; characterized by: a first releasing member mounted on the second rail, comprising an operating part having a slot, the slot being configured to abut against the blocking feature, the through hole of the second rail corresponding to the first releasing member; and a limiting member mounted on the second rail and corresponding to the first releasing member; wherein when the second chassis is mounted in the inner space of the first chassis, the limiting member is moved toward the first rail by the second chassis through the opening of the first chassis and through the through hole of the second rail, in order to further limit the first releasing member, such that the operating part of the first releasing member is not able to be pressed to move, in order to prevent the slot of the first releasing member from disengaging from the blocking feature; wherein when the second chassis is detached from the first chassis, the operating part of the first releasing member is able to be pressed to move, in order to allow the slot of the first releasing member to be disengaged from the blocking feature. a first rail comprising a blocking feature; a second rail movable relative to the first rail along a longitudinal direction, the second rail mounted on the first chassis, a through hole formed on the second rail; characterized by: a first releasing member mounted on the second rail, comprising an operating part having a slot, the slot being configured to abut against the blocking feature, the through hole of the second rail corresponding to the first releasing member; and a limiting member mounted on the second rail and corresponding to the first releasing member; wherein when the second chassis is mounted in the inner space of the first chassis, the limiting member is moved toward the first rail by the second chassis through the opening of the first chassis and through the through hole of the second rail, in order to further limit the first releasing member, such that the operating part of the first releasing member is not able to be pressed to move, in order to prevent the slot of the first releasing member from disengaging from the blocking feature; wherein when the second chassis is detached from the first chassis, the operating part of the first releasing member is able to be pressed to move, in order to allow the slot of the first releasing member to be disengaged from the blocking feature. a first releasing member mounted on the second rail, comprising an operating part having a slot, the slot being configured to abut against the blocking feature, the through hole of the second rail corresponding to the first releasing member; and a limiting member mounted on the second rail and corresponding to the first releasing member; wherein when the second chassis is mounted in the inner space of the first chassis, the limiting member is moved toward the first rail by the second chassis through the opening of the first chassis and through the through hole of the second rail, in order to further limit the first releasing member, such that the operating part of the first releasing member is not able to be pressed to move, in order to prevent the slot of the first releasing member from disengaging from the blocking feature; wherein when the second chassis is detached from the first chassis, the operating part of the first releasing member is able to be pressed to move, in order to allow the slot of the first releasing member to be disengaged from the blocking feature.