A wireless sensor network (WSN) is a collection of a large number of sensor nodes which can be networked and deployed in various applications. The representative application is tracking moving target. However, due to the unique characteristics of wireless sensor networks, there are considerable challenges in designing target tracking algorithms in these networks. This paper describes the development of collaborative signal processing techniques for targets tracking in wireless sensor networks. Based on the investigation of principles underlying target tracking in wireless sensor networks, a collaborative signal processing framework is proposed. Within this framework, various tracking algorithms have been developed. The details of the tracking algorithms and the simulation results are presented in this paper.