Disclosed herein is a method and system for managing QoS-guaranteed multimode fast mobility in wireless networks. The method includes the steps of (a) in response to a request for call establishment, registering a user ID, the unique IP address of a user, a currently used temporary IP address and the current location of the mobile host; (b) completing the call establishment; (c) establishing a tunnel between the OMS and the mobile host; (d) in response to the provision of a new temporary IP address and the wireless network information of a newly activated wireless communication interface, establishing a new tunnel using the unique IP address of the OMS and the new temporary IP address of the mobile host, and then transmitting data packets in parallel; and (e) in response to a request for the removal of a tunnel, removing the corresponding tunnel.