Provided is a method of setting a layer 3 (L3) 
handover path in a mobile IPv6 (
Internet Protocol Version 6) network while guaranteeing a flow-based QoS (
Quality of Service). The method includes receiving 
verification of QoS-related information and flow information of a mobile terminal in a home network from a 
network management system, constructing a flow 
list storing the verified flow information in the mobile terminal, and constructing a flow cache storing the verified flow information in an access 
router in the home network; transmitting the flow information by using a hop-by-hop extension header of a packet that is to be transmitted in order to allow a plurality of routers in a path between the mobile terminal and a correspondent terminal to sequentially construct a flow cache; if the mobile terminal moves to a target network, reconstructing the flow 
list of the mobile terminal and the flow cache in the access 
router in the target network, between the mobile terminal and an access 
router of the target network; adding the hop-by-hop extension header to a binding update message in order to allow a plurality of routers in a path between the mobile terminal which has moved to the target network and the access router in the home network to sequentially construct the flow cache; and adding the hop-by-hop extension header to a binding update message in order to allow a plurality of routers in a path for establishing 
direct communication between the mobile terminal and the correspondent terminal to sequentially construct the flow cache.