Disclosed is a lighting device. The lighting device includes a light emitting element, a power unit to supply power to the light emitting element, a single communication port and a processor to, when a user input signal to adjust brightness of the light emitting element is received from an external communication device connected by the single communication port, generate a control signal corresponding to the received user input signal, control the power unit to adjust brightness of the light emitting element based on the control signal, and the signal communication port may be connected to the processor via a single communication line.