An illumination device, dedicated glasses thereof, an analyzer thereof and an illumination system are provided. The illumination device includes a support member and a liquid crystal display panel mounted on the support member. The liquid crystal display panel includes a display area and a light emitting area, the liquid crystal display panel is provided with a first polarization sheet at its light incoming side in areas corresponding to the display area and the light emitting area, and is provided with a second polarization sheet at its light outgoing side only in area corresponding to the display area. The illumination device emits white light and can be used as an ordinary lamp because its light emitting area cannot be observed in the naked eye state, and when observed through the dedicated glasses or the analyzer, the content of the secret information displayed by the liquid crystal display panel can be seen.