Abstract. Target tracking is a typical and important application of wireless sensor networks (WSNs). In the consideration of scalability and energy efficiency for target tracking in large scale WSNs, it has been employed as an effective solution by organizing the WSNs into clusters. However, tracking a moving target in cluster-based WSNs suffers the boundary problem when the target moves across or along the boundary among clusters. In this paper, we propose a novel scheme, called hybrid cluster-based target tracking (HCTT), which integrates on-demand dynamic clustering into a cluster-based WSN for target tracking. To overcome the boundary problem, when the target moves close to the boundary among clusters, a dynamic cluster will be constructed for the management of target tracking. As the target moves, static clusters and on-demand dynamic clusters alternately manage the tracking task. Simulation results show that the proposed scheme performs better in tracking the moving target when ...