A CNT field emitting light source (20) is provided. The light source includes an anode (202), an anode substrate (201), a cathode (214), a cathode substrate (208), a fluorescent layer (203) and a sealing means (205). The anode is configured on the anode substrate, and the cathode is configured on the cathode substrate. The anode and the cathode are oppositely configured to produce a spatial electrical field when a voltage is applied therebetween. The cathode includes an emitter layer (206), capable of emitting electrodes bombarding the cathode and matters attached thereupon when activated and controlled by the spatial electric field, and a conductive layer (207), sandwiched between the cathode substrate and the emitter layer for providing an electrically connection therebetween. The fluorescent layer is configured on a surface of the anode oppositely facing the emitter layer, so as to produce fluorescence when bombarded by electrodes emitted from the emitter layer.