A dual mode terminal and controlling method thereof are disclosed. The present invention includes a first antenna and a second antenna. In particular, a signal received via the second antenna includes a signal generated from multiplexing an LTE downlink signal, a CDMA DCN (data core network) downlink signal and a CDMA PCS (personal communication services) downlink signal. And, the present invention is characterized in including a triplexer for demultiplexing of the downlink signals. Accordingly, a dual mode terminal of the present invention is able to receive an LTE signal without a data rate fall in the course of measuring a quality of a CDMA signal.