Provided is a User Equipment (UE) in a wireless communication system supporting a Circuit Switched FallBack (CSFB) service. The UE includes a transceiver for transmitting and receiving a signal to/from a first or second communication system that uses a different frequency; a receiver for receiving a signal from the second communication system; and a controller for controlling an operation of receiving signaling information for the CSFB service from the first communication system through the transceiver, and simultaneously measuring channel status of the second communication system using the signal received from the receiver.