In a handoff system and method for a dual mode terminal, the handoff system includes: a dual mode terminal which receives a message containing location information of a router of a second network while performing handoff from a first network to the second network, and which transmits a registration request message containing the location information of the router; and a home agent which transcodes data transmitted from a content providing server to be adapted for a bandwidth of the second network on the basis of information contained in the registration request message received from the dual mode terminal, and which transmits the transcoded data to the dual mode terminal.