A mobile terminal and a method of operating an antenna thereof are provided. The mobile terminal includes a plurality of antennas. A resonance frequency moving unit moves a resonance frequency of at least one of the plurality of antennas. And a controller controls the resonance frequency moving unit to sustain or move a resonance frequency of the at least one antenna according to use of a plurality of antennas. Therefore, by minimizing mutual interference occurring between a plurality of antennas using a similar frequency band, a wireless communication performance can be improved.