Provided are a method for performing interworking of a terminal in a wireless communications system, and a terminal using said method. The method comprises the steps of: receiving a threshold value with respect to a single parameter in which a plurality of parameters for determining whether a traffic control is performed between a first network and a second network are combined; measuring the value of the single parameter with respect to the second network; and determining whether traffic control has been performed by comparing the result of the measurement of the single parameter to the threshold value.