A scheme, designed for integration of heterogeneous data sources based on CORBA(common object request broker architecture) in a plug & play way, is put forward in this paper. An object model, named OIM(object model for integration), is proposed as the common data model for integration. The system can integrate various heterogeneous data sources, ranging from database systems, file systems, to hypertext files in World-Wide-Web. Any other data source, if wrapped according to the specified way can be integrated into the system, whenever necessary. The architecture, OIM, query processing, user interface design are introduced in some detail in the paper.