The main goal of our key project, CROWN Grid, is to empower in-depth integration of resources and cooperation of researchers nationwide and worldwide. In CROWN, Information Service is the kernel part which handles resource discovery and management process. Employing existing information service architectures suffers from poor scalability, long search response time, and large traffic overhead. In this paper, we propose a service club mechanism, called S-Club, for efficient service discovery. In S-Club, an overlay based on existing GIS mesh network of CROWN is built, so that GISs are organized as service clubs. Each club serves for a certain type of service while each GIS may join one or more clubs. Performance of S-Club is evaluated by comprehensive simulations. Simulation results show that S-Club scheme significantly improves search performance and outperforms existing approaches.