Due to the problem of information overload, locating relevant Web portals precisely based on user requirements is quite an essential task. As the need for application-to-application communication and interoperability grows, providing Web portal services that satisfy human as well as machine requirements is becoming a new challenge for Web portals. However, a Web portal capability expressing mechanism, which enables the precise location of Web portals as well as the automated discovery and invocation of Web portal services, is lacking. In this paper, we investigate how to incorporate Semantic Web technology with Web service technologies to describe the capabilities of Web portals. We also discuss the possibilities of using these descriptions for discovering and using the distributed existing portal resources.