Grid computing has emerged as a new paradigm of distributed computing technology on large-scale resource sharing and coordinated problem solving. Based on a proposed Web service-based grid architecture, we have designed a service grid middleware system called CROWN which aims to promote the utilization of valuable resources and cooperation of researchers nationwide and world-wide. To address the issues of CROWN resource management, we proposed some key technologies including trustworthy remote and hot service deployment, overlay-based distributed resource organization, resource scheduling and load balance, and federation-based virtual organization management. A status of the wide-area CROWN testbed is also introduced in this paper. Three typical applications including AREM, MDP and gViz are deployed on the CROWN testbed. Experience of CROWN testbed deployment and application development shows that the middleware can support the typical scenarios such as computing-intensive applications and data-intensive applications etc.