Abstract: The rise of cloud computing pushes web services applications to a broader platform.Cloud services are typically designed as web services and gain more attention increasingly.In order to update and expand the semantic information of cloud services,ensure quality of service and on-demand use of resources,and efficiently retrieve and manage cloud services,the paper proposes and implements a solution of cloud service library to manage a variety of cloud services which are based on water business.In the cloud service library,ontologies and metadata technology are used to formalize and depict facts and properties of cloud services,and the system also includes dynamic facet-generated mechanism to facilitate the addition of new facets,extends the semantic information of cloud services.Now,the cloud services library is applied in many projects and it shows the good application effect.