A bookcase system is provided. The bookcase system includes at least adjacently arranged two bookcase units. Each of the bookcase units further includes a first RFID reader having an antenna and placed on a first lateral side of the bookcase unit. The bookcase unit further includes a separating structure placed between two of the adjacently arranged bookcase units. The separating structure may further include at least three metal plates forming a three-layer stacked structure, and a lateral side of each of the metal plates is larger than half of a wavelength of an operating frequency of the antenna. And books are placed along a direction parallel to the lateral side.