A noise reducing earphone includes a body, a speaker, a microphone and a signal processor. The body includes a cavity and a sound tunnel. The speaker and the microphone are both disposed in the cavity. The speaker is configured for outputting audio signals through the sound tunnel. The microphone is disposed besides the speaker and configured for receiving the audio signals in the cavity. The signal processer is electrically connected to the speaker and the microphone and configured for providing an electrical signal to the speaker so that the electrical signal is converted to an audio signal by the speaker. The microphone is configured for converting the received audio signals to an electrical signal, and sending the electrical signal to the signal processor. The signal processor is configured for outputting to the speaker an anti-phase signal with respect to the noise component defined by the signal processor in the audio signal.