This paper introduces the design of a GIS component software - MapManager, which is based on the COM technology and conformed to OpenGIS specifications. In the process of GIS software design, the following aspects should be considered carefully: spatial database, visualization, data exchange, system function like data querying, editing and mapping. MapManager is proven to be an applicable GIS component software because some professional applications have been developed with it. In the last, the author discusses the shortcomings of the software and identifies the need for future research in the integration with DBMS.