The information service is a key component of a grid environment and critical to the operation of a computational grid. In this work, an OGSA (Open Grid Services Architecture) based information service that complies with OGSI (Open Grid Services Infrastructure) is presented. The main functionality of this information service is the provision of information essential for applications running on a computational grid such as resource information, job status, resource workload, service meta-information, and queue status. This OGSI-compliant information service is built on Globus Toolkit MDS-3, and it works with meta-scheduling services and local job scheduling systems to support resource discovery, job scheduling, and execution management. In this paper, the architecture of the Information Service and the models of information data organization are presented. Some implementation issues are discussed as well.