A mounting assembly for a data storage device includes a data storage device, a base, a locking member, an operating member, a driving member and a resilient element. The data storage device includes a rear wall and a clipping member mounted to the rear wall. The base includes a bottom plate. The locking member and the driving member are slidably assembled on the bottom plate. The locking member engages with the clipping member to mount the data storage device in the base. The operating member is attached to the locking member on an opposite surface of the bottom plate. The driving member is driven by the locking member to push the data storage device out a certain distance. The resilient element retains the locking member at a locking position and drives the locking member back after the locking member is at an unlocking position.