A mounting apparatus for a disk drive includes a tray, a bracket, and a latch member. The tray supports the disk drive. A resiliently deformable hook is formed on the tray. The tray defines two pair of first and second sliding slots. The bracket receives the tray and the disk drive, and defines a positioning opening. Two pair of posts are formed at two opposite ends of the latch member. The posts slide and rotate in the sliding slots. A positioning tab is formed the latch member and engages in the positioning opening to prevent the tray sliding out of the bracket. A blocking tab is formed on the latch member, and engages with the hook to remain engagement between the positioning tab and the positioning opening, and to disengage from the hook when the hook is deformed.