A storage device assembly includes a storage device (50) with a fastener (524) thereon, a bracket (10) for accommodating the storage device and an operating member (40) slidably attached to the bracket. The bracket defines a guiding hole (166) for the fastener of the storage device inserting therethrough. The operating member includes a latching portion (426) and a deflectable mounting portion (46). The operating member has a locked position in which the latching portion engages with the fastener, and a unlocked position in which the mounting portion is biased to disengage the latching portion from the fastener.