A slide rail assembly, comprising: a first rail comprising a blocking part; a second rail movable relative to the first rail; comprising: a first locking device arranged on the second rail, the first locking device comprising a first member and a second member, the first member comprising a first part and a first elastic section, the second member comprising a second part and a second elastic section, the first elastic section and the second elastic section being tilted relative to the second rail, a first space being defined between the first part and the second part, wherein the first part is arranged at an end of the first elastic section, the second part is arranged at an end of the second elastic section, the first elastic section is located between the second rail and the second elastic section; and a second locking device arranged on the second rail, the second locking device comprising a third member and a fourth member, the third member comprising a third part and a third elastic section, the fourth member comprising a fourth part and a fourth elastic section, the third elastic section and the fourth elastic section being tilted relative to the second rail, a second space being defined between the third part and the fourth part, wherein the third part is arranged at an end of the third elastic section, the fourth part is arranged at an end of the fourth elastic section, the third elastic section is located between the second rail and the fourth elastic section; wherein when the second rail is moved relative to the first rail from a retracted position to a first predetermined position along a first direction, the first space is configured to accommodate the blocking part of the first rail, such that the blocking part is locked by the first locking device; wherein when the first locking device is operated to unlock the blocking part, and the second rail is moved relative to the first rail from the first predetermined position to a second predetermined position along the first direction, the second space is configured to accommodate the blocking part of the first rail, such that the blocking part is locked by the second locking device. a first rail comprising a blocking part; a second rail movable relative to the first rail; comprising: a first locking device arranged on the second rail, the first locking device comprising a first member and a second member, the first member comprising a first part and a first elastic section, the second member comprising a second part and a second elastic section, the first elastic section and the second elastic section being tilted relative to the second rail, a first space being defined between the first part and the second part, wherein the first part is arranged at an end of the first elastic section, the second part is arranged at an end of the second elastic section, the first elastic section is located between the second rail and the second elastic section; and a second locking device arranged on the second rail, the second locking device comprising a third member and a fourth member, the third member comprising a third part and a third elastic section, the fourth member comprising a fourth part and a fourth elastic section, the third elastic section and the fourth elastic section being tilted relative to the second rail, a second space being defined between the third part and the fourth part, wherein the third part is arranged at an end of the third elastic section, the fourth part is arranged at an end of the fourth elastic section, the third elastic section is located between the second rail and the fourth elastic section; a first locking device arranged on the second rail, the first locking device comprising a first member and a second member, the first member comprising a first part and a first elastic section, the second member comprising a second part and a second elastic section, the first elastic section and the second elastic section being tilted relative to the second rail, a first space being defined between the first part and the second part, wherein the first part is arranged at an end of the first elastic section, the second part is arranged at an end of the second elastic section, the first elastic section is located between the second rail and the second elastic section; and a second locking device arranged on the second rail, the second locking device comprising a third member and a fourth member, the third member comprising a third part and a third elastic section, the fourth member comprising a fourth part and a fourth elastic section, the third elastic section and the fourth elastic section being tilted relative to the second rail, a second space being defined between the third part and the fourth part, wherein the third part is arranged at an end of the third elastic section, the fourth part is arranged at an end of the fourth elastic section, the third elastic section is located between the second rail and the fourth elastic section; wherein when the second rail is moved relative to the first rail from a retracted position to a first predetermined position along a first direction, the first space is configured to accommodate the blocking part of the first rail, such that the blocking part is locked by the first locking device; wherein when the first locking device is operated to unlock the blocking part, and the second rail is moved relative to the first rail from the first predetermined position to a second predetermined position along the first direction, the second space is configured to accommodate the blocking part of the first rail, such that the blocking part is locked by the second locking device.