Since many grid applications access data from file system or database systems, the management of data within grids is an essential problem. In this work, we address the necessity of grid file system and propose OGSA based grid file system(OGSA-GFS). OGSA-GFS integrates and manages distributed files and replicated files across multiple institutions in Grids. And it provides the global view of the files to users. This global view is used to access the distributed files for grid user or grid application regardless of the physical filename and host address. In order to provide the global view and standard interface, we design three main services, the GFS namespace service, the GFS replica management service, and the GFS information service, and implement these services on the OGSA..