As industrial structure of OECD has change from the manufacturing industry to service industry rapidly, the proportion of the service industries have become nearly 70 percent. The service science is the newest science that searches intrinsic qualities of the service industry, innovates service levels, and includes knowledge of the service management, the service marketing and the service engineering, therefore develops related fields. Framework of the service science, Service Oriented Architecture (SOA) has been making sure of its position rapidly. This paper proposed a plan that SOA could be applied to the service industry through a prototype design of the Travel Agency System based on SOA for Business Models. The analysis of requirements is proceeded by Unified Modeling Language and SOA delivery strategy is selected the top-down strategy, service candidates and operations can be derived through analyzing detailed process of each use case, these can be abstracted at two service layers for effective implementation. Travel Agency System was designed by means of WSDL, XML-based language that describes Business Service and provides a approaching means between Businesses electrically.