A drive bracket assembly for carrying data storage devices, includes a first carrying bracket having a pair of side walls, a second carrying bracket mounted in the first carrying bracket, and a locking latch. The second carrying bracket includes a pair of side walls. A securing member including a first blocking tab formed on each side wall of the second carrying bracket. A locking latch is resiliently and moveably attached to one of the side walls of the first carrying bracket. A blocking member corresponding to the first blocking tab of the securing member is formed on the locking latch, for preventing a movement of the second carrying bracket along a first direction parallel to the side walls of the first carrying bracket. The first carrying bracket can be mounted in the first carrying bracket for carrying small type data storage devices. The second carrying bracket can be removed from the first carrying bracket so that the first carrying bracket can hold more large type data storage devices.