Provided are a dual mode terminal for supporting an access in a different network, a network apparatus, and an operation method thereof. The dual mode terminal may include: an interface to receive first network information from a first network apparatus and to receive second network information from a second network apparatus in response to each network information request; a selection unit to select a single network apparatus based on the first network information and the second network information; and a processing unit to transmit a call connection request to the selected network apparatus, and to control a communication with the selected network apparatus depending on whether the selected network apparatus allows a call connection.