A lighting device, a lighting panel and a circuit board thereof are provided. The circuit board comprises a substrate; a plurality of light sources disposed on the substrate and at least one circuit layer, being patterned onto the substrate to form a plurality of traces for electrically connecting the light sources. Therein, the circuit board is capable of being assembled with other circuit boards to construct the lighting panel. The lighting device is capable of having the lighting panel of a large size by assembling a plurality of the circuit boards and individually controlling each light source disposed on the lighting panel so as to provide the function of local dimming.