Disclosed herein is an organic light emitting diode (OLED) lighting device capable of expressing characters or drawings with various colors. The OLED lighting device according to aspects of the present disclosure includes a thermochromic pattern arranged inside or outside of a substrate, the thermo chromic pattern having a property of changing a color thereof according to a change in temperature. By applying a reversible thermochromic pattern, which may maintain or lose an original color thereof according to a temperature change, to the inside or outside of the substrate, it is possible to express characters and drawings with various colors without designing a processing pattern inside the substrate.