Abstract: The grid information service system is a very important part of grid computing. An old grid information service system needs to be reconstructed as a result of the combination of grid and web service. This paper discussed quondam grid information service systems such as MDS, R-GMA and Hawkeye and substantially analyzed the specification of open grid services architecture (OGSA). An OGIS (grid information system based on OGSA) with forest structure was constructed, the functions and means of realization of OGIS modules were presented, and the key technologies and solutions to OGIS were described. OGIS provides an effective blue print for developing a grid information service system.