An illuminated keyboard includes a light-emitting diode light string, a controller, a feedback line and a plurality of keys. The light-emitting diode light string includes a plurality of light-emitting diode modules which are connected in series through a serial connection wire. Each light-emitting diode module includes a light-emitting diode chip and a drive circuit. The controller is electrically connected with the light-emitting diode light string. The feedback line is electrically connected between the light-emitting diode modules and the controller. The keys correspond to the light-emitting diode modules and are electrically connected with the feedback line. Each light-emitting diode module emits light according to a received light-emitting signal and outputs a feedback signal. When at least one of the keys is switched to a pressing state, the feedback signal is pulled from a first level to a second level for the controller to differentiate the key in the pressing state.