A slide rail assembly comprising: a first rail comprising a blocking feature; a second rail movable with respect to the first rail; a first working member arranged on the second rail; a first operating member configured to operate the first working member; and a blocking member (48, 200) arranged on the second rail; wherein when the second rail is located at a predetermined position with respect to the first rail and the first working member is in a first state, the first working member and the blocking feature block each other for restraining the second rail from moving toward a first predetermined direction from the predetermined position; wherein when the blocking member (48, 200) is in a blocking state (K1, K1'), the blocking member (48, 200) blocks the first operating member for restraining the first operating member from driving the first working member to disengage from the first state; wherein when the blocking member (48, 200) is in a non-blocking state (K2, K2'), the blocking member (48, 200) does not block the first operating member for allowing the first operating member to drive the first working member from the first state to a second state, and when the first working member is in the second state, the first working member and the blocking feature do not block each other for allowing the second rail to move toward the first predetermined direction from the predetermined position; further characterized by a second working member and a second operating member, the second working member being arranged on the second rail, the second operating member being configured to operate the second working member, when the second rail is located at the predetermined position with respect to the first rail and the second working member is in a third state, the second working member and the blocking feature blocking each other for restraining the second rail from moving toward a second predetermined direction from the predetermined position. a first rail comprising a blocking feature; a second rail movable with respect to the first rail; a first working member arranged on the second rail; a first operating member configured to operate the first working member; and a blocking member (48, 200) arranged on the second rail; wherein when the second rail is located at a predetermined position with respect to the first rail and the first working member is in a first state, the first working member and the blocking feature block each other for restraining the second rail from moving toward a first predetermined direction from the predetermined position; wherein when the blocking member (48, 200) is in a blocking state (K1, K1'), the blocking member (48, 200) blocks the first operating member for restraining the first operating member from driving the first working member to disengage from the first state; wherein when the blocking member (48, 200) is in a non-blocking state (K2, K2'), the blocking member (48, 200) does not block the first operating member for allowing the first operating member to drive the first working member from the first state to a second state, and when the first working member is in the second state, the first working member and the blocking feature do not block each other for allowing the second rail to move toward the first predetermined direction from the predetermined position; further characterized by a second working member and a second operating member, the second working member being arranged on the second rail, the second operating member being configured to operate the second working member, when the second rail is located at the predetermined position with respect to the first rail and the second working member is in a third state, the second working member and the blocking feature blocking each other for restraining the second rail from moving toward a second predetermined direction from the predetermined position.