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, a passage being defined by the upper wall, the lower wall and the longitudinal wall; a second rail movably mounted in the passage of the first rail; a slide assisting device in the form of a bearing retainer configured to assist in relative movement between the second rail and the first rail; an engaging member arranged on a first area of the longitudinal wall of the first rail; a blocking structure arranged on a second area of the longitudinal wall of the first rail; and at least one supporting structure arranged on the first rail; wherein the first area and the second area are spaced apart from each other along a longitudinal direction of the first rail by a predetermined longitudinal distance, the first area is further away from a passage entrance of the passage than the second area; the slide rail assembly further comprising: a first working member operatively connected to the second rail, wherein when the second rail is moved relative to the first rail from a retracted position to an open position along a first direction, the second rail is configured to be blocked by the blocking structure through the first working member in a predetermined state, in order to prevent the second rail from being moved from the open position along the first direction; when the first working member is operated to be no longer in the predetermined state, the second rail is movable from the open position along the first direction to be outside the passage of the first rail; during a process of the second rail being moved relative to the first rail from the retracted position along the first direction to be outside the passage of the first rail, the slide assisting device is configured to be engaged with the engaging member in response to movement of the second rail; and during a process of the second rail being moved from outside of the passage of the first rail toward the retracted position along a second direction through the passage entrance of the first rail, the at least one supporting structure is configured to support the second rail; and characterized in that the first working member is pivoted to the second rail, and the slide rail assembly further comprises an elastic base having a first elastic part configured to provide an elastic force to the first working member, and a second working member pivoted to the second rail; wherein the elastic base further has a second elastic part configured to provide an elastic force to the second working member; when the second rail is located at the open position relative to the first rail, the first working member and the second working member are configured to be located at two opposite sides of the blocking structure respectively. a first rail comprising an upper wall, a lower wall and a longitudinal wall connected between the upper wall and the lower wall, a passage being defined by the upper wall, the lower wall and the longitudinal wall; a second rail movably mounted in the passage of the first rail; a slide assisting device in the form of a bearing retainer configured to assist in relative movement between the second rail and the first rail; an engaging member arranged on a first area of the longitudinal wall of the first rail; a blocking structure arranged on a second area of the longitudinal wall of the first rail; and at least one supporting structure arranged on the first rail; wherein the first area and the second area are spaced apart from each other along a longitudinal direction of the first rail by a predetermined longitudinal distance, the first area is further away from a passage entrance of the passage than the second area; the slide rail assembly further comprising: a first working member operatively connected to the second rail, wherein when the second rail is moved relative to the first rail from a retracted position to an open position along a first direction, the second rail is configured to be blocked by the blocking structure through the first working member in a predetermined state, in order to prevent the second rail from being moved from the open position along the first direction; when the first working member is operated to be no longer in the predetermined state, the second rail is movable from the open position along the first direction to be outside the passage of the first rail; during a process of the second rail being moved relative to the first rail from the retracted position along the first direction to be outside the passage of the first rail, the slide assisting device is configured to be engaged with the engaging member in response to movement of the second rail; and during a process of the second rail being moved from outside of the passage of the first rail toward the retracted position along a second direction through the passage entrance of the first rail, the at least one supporting structure is configured to support the second rail; and characterized in that the first working member is pivoted to the second rail, and the slide rail assembly further comprises an elastic base having a first elastic part configured to provide an elastic force to the first working member, and a second working member pivoted to the second rail; wherein the elastic base further has a second elastic part configured to provide an elastic force to the second working member; when the second rail is located at the open position relative to the first rail, the first working member and the second working member are configured to be located at two opposite sides of the blocking structure respectively.