SIGN-BASED SEMANTIC INTEROPERABILITY FOR WEB SERVICES by Li Chenglin Thesis Supervisor: Associate Professor, Guo Jingzhi Master of Science in E-Commerce Technology Semantic service is an extension of the SOA web service, which adds the capability of semantics. Existing semantic services cannot solve problems like semantic interoperability between heterogeneous web services and ontologies. This paper aims at designing a vocabulary-based semantic web approach via collaborative conceptualization system, which enables heterogeneous web services to be semantically discovered, interoperable, and exchange information among different ontologies. Based on this approach, a SSWS standard is implemented and used to support the services, with which clients can exchange their data in the heterogeneous web environment.