The present invention provides a flat panel display device, which includes a backlight system and a display panel. The backlight system includes a reflector plate and a back frame that carries the reflector, wherein the back frame includes at least two primary assembling pieces, the at least two primary assembling pieces being joined to form a main frame structure of the back frame; and the reflector plate includes a substrate layer and a reflection layer formed on the substrate layer, the substrate layer having a surface that is away from the reflection layer and comprises an ink layer printed thereon. The present invention also provides a stereoscopic display device. With the above arrangement, the present invention provides a flat panel display device and a stereoscopic display device having an ink layer printed on the surface of the substrate layer that is away from the reflection layer in order to eliminate light leakage from the surface of the reflector plate that faces the back frame, reduce the potential risk of light leakage after the assembling of the backlight system, and thereby improve the performance of the flat panel display device and the stereoscopic display device.