A blank dummy structure adaptable for slide rails and absence of slide rails, the blank dummy structure includes a main plate, two buckles, two rotating members, and two fasteners. The buckle comprises a snap component, the snap component is connected with the main plate to slide between first and second positions on the main plate. The rotating member and the snap component are arranged on the same side of the main plate, the rotating member on the main plate, comprises a limiting component. the rotating member being rotatably connected with the main plate to rotate the rotating member between a limit position and an avoidance position. The fastener configured to cooperate with the rack when the rotating member is in the avoidance position. The buckle, the rotating member, and the fastener are mounted on the main plate. A rack is also disclosed.