An apparatus and a method for reducing cross-talk between audio channels in a mobile terminal are provided. The apparatus includes an ear jack, a radio signal tuner, a baseband, and a switching unit. The ear jack includes a common port for a reference potential of an earphone and a radio signal. The radio signal tuner processes a radio signal input via the common port. The baseband determines an on/off state of a radio reception function to output a control signal. The switching unit connects the common port of the ear jack to one of a ground and the radio signal tuner according to the control signal.