A mounting apparatus for a data storage device (10) with mounting holes (111) in a side wall (11) includes a bracket (20) and a locking member (30). A resilient clip (222) extends from the bracket. An operating portion (2222) protrudes from a free end of the resilient clip. A retaining tab (2221) protrudes from the free end of the resilient clip for engaging into the mounting hole of the data storage device. The locking member is slidably secured to the bracket, and a pushing portion (34) is formed in the locking member for lifting the operating portion to disengage the retaining tab from the mounting hole of the data storage device.