A communication method for a mobile terminal to perform seamless handover between a WWAN and a WLAN. The method comprises receiving a registration message sent by the mobile terminal when it enters the WLAN, wherein the registration message at least contains a WLAN address that the mobile terminal acquires when entering the WLAN; establishing the mapping relationship between the WWAN address and the WLAN address of the mobile terminal according to the registration message; encapsulating the WLAN address into the data information to be sent to the mobile terminal according to the mapping relationship when receiving the data information to be sent to the mobile terminal from a source address; and sending the data information containing the WLAN address to the mobile terminal via the WLAN.