An earphone antenna of a portable terminal having enhanced reception sensitivity even when a wearing state of the earphone of the mobile terminal is changed is provided. The earphone antenna includes a plurality of voice signal lines, an insulating sheath configured to cover an outer surface of the plurality of the voice signal lines, a receptacle configured to connect to a first end of each of the plurality of the voice signal lines, and a ground and antenna line including a first antenna line configured to wind around an outer surface of the insulating sheath at a first interval in a spiral form, the first antenna line having a first thickness, wherein the ground and antenna line includes a second antenna line configured to wind around an outer surface of the receptacle at a second interval in the spiral form, the second antenna line having a second thickness that is greater than the first thickness and the second interval being different from the first interval.