A circuit apparatus for recognizing an earphone in a mobile terminal is provided. The apparatus includes a plurality of devices, a wiring for recognizing the number of poles of the earphone, and a comparator. The plurality of devices are connected between a microphone bias power and a wiring that receives a signal from a microphone of an earphone. The wiring that recognizes the number of poles of the earphone branches from a wiring between at least two of the devices. The comparator compares a voltage of the wiring that recognizes the number of poles with a reference voltage to output a result signal.