Abstract: The proxy mobile IPv6 protocol (PMIPv6) is a network-based mobility management protocol proposed by IETF. It has been adopted by many standard organizations and will be one of the most important components of the next generation mobile network. PMIPv6 provides mobility management for IPv6 nodes without host involvement. But it only defines how mobility entities manage hosts’ intra-domain mobility and lacks QoS control. To solve this problem, we propose a flow-based differentiated service scheme in PMIPv6 networks (FD-PMIPv6) . To implement differentiated service for different flows in the PMIPv6 domain, we introduce a logical tunnel based flow separation method, as well as a binding method between flows and logical tunnels. With the proposed separation method, multiple tunnels can be established between a pair of mobility management entities and each one has a specific service type. With the binding method between flows and logical tunnels, mobility management entities could bind flows to particular logical tunnels according to their QoS requirements and network status. The simulation results based on NS2 show that, FD-PMIPv6 can provide differentiated services for different flows, thus it can meet the specific QoS requirements of different flows more efficiently compared with PMIPv6.