The combination of large data set size, geographic distribution of resources and users, and sophisticated applications on data and information needs robust infrastructures. In this paper, Knowledge Management Sphere (KMSphere) is proposed and developed to explore important aspects of service-oriented and ontology-driven knowledge management on the grid. The main idea of KMSphere is to integrate ontologies with a service-oriented grid, build a knowledge space on top of databases, and then organize, utilize, and manage the knowledge resources in that space.