In information retrieval, thesauri have increasingly become vital as an aid to effective retrieval. In the networked environment, terminology services become an ideal way to employ thesauri in application systems. However, most of existing projects or systems focused mainly on the construction of terminology services and seldom gave attention to their usage. The overall purpose of this study is to investigate the construction of terminology services and their usage. Firstly, taking Chinese Thesaurus as a source vocabulary, a system was built with the use of REST architecture and Semantic Web technologies. After the construction of terminology services, this study used the above mentioned six terminology services to investigate the usage of terminology services in information retrieval systems based on the embedded client. Taking the get Synonym service as an example, the usefulness of terminology services was tested with an experiment of 30 user queries to the library OPAC system and Baidu Search Engine. OPAC’s experiment results showed that the average recall increases 26.7% while the average precision decreases 4.6%. Baidu’s experiment results showed that the P@5 precision increases 16%. Four usage modes were designed, including multiple choice for query expansion, single choice for query replacement, hybrid of query expansion and replacement, and automatic query expansion. To evaluate their usability, a user testing was carried out in the library OPAC system and Baidu Search Engine with 24 human subjects based on four usability criteria(effectiveness, efficiency, user satisfaction and learnability). The evaluation results showed that multiple choice for query expansion was the best usage mode which is more effective, easier to use, easier to learn, and has higher user satisfaction. In the networked environment, terminology services become an ideal way to employ thesauri in application systems. However, most of existing projects or systems focused mainly on the construction of terminology services The overall purpose of this study is to investigate the construction of terminology services and their usage. First, taking Chinese Thesaurus as a source vocabulary, a system was built with the use of REST architecture and Semantic Web technologies After the construction of terminology services, this study used the above mentioned six terminology services to investigate the usage of terminology services in information retrieval systems based on the embedded client. Taking the get Synonym service as an example, the usefulness of terminology services was tested with an experiment of 30 user queries to the library OPAC system and B aidu Search Engine. OPAC’s experiment results showed that the average return increases 26.7% while the average precision decreases 4.6%. Baidu’s experiment results showed that the P 5 precision increases 16%. Four usage modes were designed, including multiple choice for query expansion, single evaluation for query replacement, hybrid of query expansion and replacement, and automatic query expansion. To evaluate their usability, a user testing was carried out in the library OPAC system and Baidu Search Engine with 24 human subjects based on four usability criteria (effectiveness, efficiency, user satisfaction and learnability). The evaluation results showed that multiple choice for query expansion was the best usage mode which is more effective, easier to use, easier to learn, and has higher user satisfaction.