Nowadays, wireless sensor network (WSN) is becoming popular in various fields of different industries along with the rapid development of hardware and software. Whereas more and more WSN applications come into use has make it difficult for consumers especially those who do not have professional knowledge to use. So it is urgently necessary and significant to offer services which do not need professional knowledge to satisfy consumers’ requirements from the users’ point of view. Therefore, service oriented architecture (SOA) is introduced as a method to do our research from the users’ point of view. After asimple overall introduction of WSN which include the system architecture, hardware, software and supported technologies, we pay our emphasis on the power consumption modeling for WSN and get some formulations following the operation cycle. Last but not least, SOA method is analyzed and some SOA based WSN applications are introduced as examples to further understand of SOA based WSN for readers.