A mounting apparatus for a hard disk drive includes a bracket and a resilient plate. The bracket includes a first and a second side plates each defining two slanted first notches, and two first slots respectively extending from rear ends of the first notches. The resilient plate is slidably mounted to the first side plate. A front end of the resilient plate defines a slanted second notch, and a semicircular second slot extending from a rear end of the second notch. When the resilient plate is at a first position, the second notch and the second slot respectively align with one of the first notches and a corresponding first slot of the first side plate. When the resilient plate is slid to a second position, the second slot aligns with a rear end of said corresponding first slot, and the second notch is staggered from the corresponding first notch.