A slide rail assembly, comprising: a rail member; and a first bracket device displaceable with respect to the rail member; wherein the first bracket device is provided with a first structure, and the rail member is provided with a second structure; wherein the first structure and the second structure are configured to be blocked by each other when the first bracket device and the rail member are at a predetermined position with respect to each other; one of the first structure and the second structure is an elastic member; when the first structure and the second structure are blocked by each other, and an external force applied to effect relative displacement between the first bracket device and the rail member is less than a force generated by the elastic member, the first bracket device and the rail member are prevented from displacement with respect to each other in either of a first direction and a second direction; and when the first structure and the second structure are blocked by each other, and the external force applied to effect relative displacement between the first bracket device and the rail member is greater than the force generated by the elastic member, said blockage of the first structure and the second structure by each other is removed in a non-destructive manner; wherein the first direction and the second direction are opposite directions; wherein the other of the first structure and the second structure is a space; the elastic member includes a connecting portion, an operating portion, and an elastic portion located between the connecting portion and the operating portion; the connecting portion is connected to one of the first bracket device and the rail member; the elastic portion includes a first blocking section and a second blocking section; and when the first bracket device and the rail member are at the predetermined position with respect to each other, the first blocking section and the second blocking section of the elastic portion of the elastic member correspond to a first wall portion and a second wall portion of the space respectively to prevent the first bracket device and the rail member from displacement with respect to each other in either of the first direction and the second direction; wherein when the first bracket device and the rail member are at the predetermined position with respect to each other, and the elastic member is operated, the first blocking section and the second blocking section of the elastic portion of the elastic member are stopped from corresponding to the first wall portion and the second wall portion of the space respectively, thereby allowing the first bracket device and the rail member to be displaced with respect to each other in either of the first direction and the second direction. a rail member; and a first bracket device displaceable with respect to the rail member; wherein the first bracket device is provided with a first structure, and the rail member is provided with a second structure; wherein the first structure and the second structure are configured to be blocked by each other when the first bracket device and the rail member are at a predetermined position with respect to each other; one of the first structure and the second structure is an elastic member; when the first structure and the second structure are blocked by each other, and an external force applied to effect relative displacement between the first bracket device and the rail member is less than a force generated by the elastic member, the first bracket device and the rail member are prevented from displacement with respect to each other in either of a first direction and a second direction; and when the first structure and the second structure are blocked by each other, and the external force applied to effect relative displacement between the first bracket device and the rail member is greater than the force generated by the elastic member, said blockage of the first structure and the second structure by each other is removed in a non-destructive manner; wherein the first direction and the second direction are opposite directions; wherein the other of the first structure and the second structure is a space; the elastic member includes a connecting portion, an operating portion, and an elastic portion located between the connecting portion and the operating portion; the connecting portion is connected to one of the first bracket device and the rail member; the elastic portion includes a first blocking section and a second blocking section; and when the first bracket device and the rail member are at the predetermined position with respect to each other, the first blocking section and the second blocking section of the elastic portion of the elastic member correspond to a first wall portion and a second wall portion of the space respectively to prevent the first bracket device and the rail member from displacement with respect to each other in either of the first direction and the second direction; wherein when the first bracket device and the rail member are at the predetermined position with respect to each other, and the elastic member is operated, the first blocking section and the second blocking section of the elastic portion of the elastic member are stopped from corresponding to the first wall portion and the second wall portion of the space respectively, thereby allowing the first bracket device and the rail member to be displaced with respect to each other in either of the first direction and the second direction.