The emergence of low-cost and mature technologies in wireless communication, visual sensor devices, and digtial signal processing, facilitates the potential of wirelss sensor networks (WSN). Like sensor networks which respond to sensory information such as temerpature and humidity, WSN interconnects autonomous devices for capturing and processing video and audio sensory information. This thesis highlights the following topics: (1) a summary of applications and challenges of WVSN; (2) the performance analysis of a wireless sensor network and wireless multimedia sensor network. To extend the system performance, two methods are provided in this thesis. First, mobile sink with node scheduling in multiple tracking targets is proposed. Second, a layered clustering model in sparing communication energy consumption in wirelsess visual sensor network is proposed. The experimental results validate our correlated approaches extend the system lifetime; (3) direction for Future Research are given.