A hard disk drive bracket is configured to be fixed within a hard disk drive holder and includes a support portion, a tray and an elastic piece. The tray is connected to a side of the support portion and has a chassis and a sidewall protruding form a side of the chassis. The elastic piece is suspended above the tray and has a first end fixed to the support portion and a second end forming a hook. The elastic piece and the tray form a holding space therebetween for holding a hard disk drive. When the hard disk drive is inserted into the chassis along a bending direction of the second end of the elastic piece, the second end lifts to hold the hard disk drive between the chassis and the elastic piece. The sidewall fixes the hard disk drive on the chassis with the cooperation of the elastic piece.