Web Services are considered a new way of building software applications based on Services that are available through the Internet. However, Web Services still face many problems that are limiting their adoption. One of the causes of this problem is the lack of metadata about the quality attributes of Web Services, which make Service Requesters reluctant to integrate Web Service with their applications. This paper proposes a novel ontology that describes a model of the requester-oriented Web Services' quality attributes. The ontology is based on previous quality models which have been refined and modified specifically to address the quality issues as they relate to the requester of Web Services. Also an analysis will describe how some of the quality attributes in the previous model can be evaluated using different types of test cases.