Web services integrate various business application systems to provide worldwide platform to serve customers directly over the Internet. As the increasing number of business applications joining into the integration, the service activities are involving more and more complex situations. The enormous workload and the complex business processes involved by a request cannot be dealt with the simple request-answer model. It is highly desirable that Web services system can support vast clients? requests efficiently, effectively and promptly. This paper provides a searching mechanism to serve clients intelligently. It utilizes an efficient matchmaker to discover clients? requests by reusing past experiences. The matchmaker is enhanced by an automated discovery algorithm. It uses not only OWL-S for identifying different matching levels by related domain ontologies but also is enhanced with reuse mechanism of case-based reasoning (CBR) with a formula for similarity. The proposed matchmaker takes advantages of semantics and CBR techniques to improve the efficiency and effectiveness of Web services searching.