Recently the research about heterogeneous database access and integration is booming in grid technology and related applications.UDMGrid(university digital museum grid)is devoted to the integration and sharing of resources from 12 university digital museums with grid technology,and it is necessary for UDMGrid to investigate the mechanism and method for heterogeneous specimen-database access and integration.In this paper,an effective schema-reusable method on database access and integration in UDMGrid(UDMGrid-DAI)is presented.It includes a schema-reusable virtual database to define the global uniform or heterogeneous database resources,and to describe the concepts and their relations of one or one sort of scientific domain through virtual tables and virtual columns.It also includes the ways of database registering and query mapping to the virtual databases based on the above virtual database mechanism.Furthermore,This UDMGrid-DAI provides a consistent interface to the virtual databases through the registry processing and the virtual database services.Finally,the experimental results demonstrate the work of this paper,and show that this schema-reusable mechanism of virtual database is correct and useful on database access and integration,especially in UDMGrid.