Efficiently finding Web services on the Web is a challenging issue in service-oriented computing. Currently, UDDI is a standard for publishing and discovery of Web services, and UDDI registries also provide keyword searches for Web services. However, the search functionality is very simple and fails to account for relationships between Web services. Firstly, users are overwhelmed by the huge number of irrelevant returned services. Secondly, the intentions of users and the semantics in Web services are ignored. Inspired by the success of partitioning approach used in the database design, we used a novel clustering semantic algorithm to eliminate irrelevant services with respect to a query. Then we utilized Probabilistic Latent Semantic Analysis (PLSA), a machine learning method, to capture the semantics hidden behind the words in a query, and the descriptions in the services, so that service matching can be carried out at the concept level. This paper reports upon the preliminary exper...