Abstract: In order to realize a large-scale digital library interoperability on Internet, a grid technology based framework is put forward,a digital library grid,which is based on OAI-PMH framework,and an architecture with three levels for DL grid is given.To construct the DL grid,some crucial technologies are discussed,designed and achieved,such as discovering and harvesting of metadata resources,re-building of metadata resources and utilization of metadata resources.Through using integrated metadata resources,the system realizes information sharing of digital libraries on Web.