A mounting apparatus for mounting a data storage device that defines a locking hole in a sidewall thereof includes a bracket for holding the data storage device, and a locking member. The bracket includes a first side wall defining a through-hole. The locking member includes a mounting member mounted to the first side wall of the bracket, and a securing member rotatably mounted to the mounting member. The securing member includes a post extending therefrom. The securing member is selectively located in two positions. In a first position, the post passes through the through-hole of the bracket to engage with the locking hole of the data storage device. In a second position, the post is disengaged from the locking hole.