Abstract: How to select and combine the services from available ones with similar functions appropriately and efficient1y to provide much better services for users is an important yet difficult issue in SOA. The rationality of service composition is improved to a certain extent with the introduction of Quality of Service(QoS). However, there is still no effident way to ensure the trustworthiness of the service composition. With such an observation in mind, a Trust Web Service Composition Modcl(hWSCM) was proposed to enhance the trustworthiness of service composition. hhis was achieved by adding QoS agents and trust control module to existing typical Web service composition models. Finally, experiments were conducted on the Language Grid (http://langrid. nict.go. jp). The experimental results show that the proposed approach can provide trustworthy composite services with high quality.

Key words: Web service, Service composition, Quality of service, Trustworthy, Language grid