SUMMARYPosition information is of vital importance in the various applications in energy‐constrained wireless sensor networks. It has to design a localization mechanism considering both precision and energy consumption factors. In this paper, we propose a hybrid localization system in wireless sensor networks, which is composed of coarse‐grained localization system and fine‐grained localization system. The coarse‐grained localization system takes the wireless signal strength as the reference for distance and gets the rough region as the unknown node. The fine‐grained localization system is in charge of location refinement that takes image to localize the unknown node with camera sensor nodes. On the basis of the hybrid localization system, we furthermore design a hybrid tracking system for localizing a moving object. Finally, we build up a test bed to conduct experiments with our developed sensor network. The experiment results show that the proposed hybrid localization and tracking system can achieve high position precision and low energy consumption. Copyright © 2012 John Wiley & Sons, Ltd.