Disclosed is a method for selecting a communication network by a wireless terminal, the method including receiving a signal having a predetermined reception power level from one or more communication networks, and calculating a guaranteed data rate of each of said one or more communication networks by using the predetermined reception power level of the signal; comparing the calculated guaranteed datarate with a minimum guaranteed datarate; and calculating a selection factor value of each of said one or more communication networks by using the guaranteed datarate when all guaranteed datarate of said one or more communication networks are equal to or greater than the minimum guaranteed datarate, and selecting a communication network having a lowest selection factor value.