The Grid is the leading technology that integrates the heterogeneous computing resources into a single virtual computing environment. However, it is still challenging to scientists and site administrators because it deals with the different underlying physical resources such as different hardware platforms, different batch queueing systems, and even different user administration policies. To provide the easy-to-use access to the Grid environment, we have developed a web-based Grid service platform called K*Gate. It is based on Java technology for adapting heterogeneous architectures on the Grid. This system consists of Grid job management system to provide a virtualized workspace on the heterogeneous computational resources, Grid monitoring system to provide a unified resource monitoring functionality, and Grid accounting system to provide an integrated resource usage accounting on the Grid. K*Gate has deployed on the K*Grid infrastructure, nation-wide Grid infrastructure in Korea.