This paper presents new style maps, called dynamic maps, based on view functions of geographic databases. The dynamic maps contain two basic components, (1) queries applied to geographic databases and (2) visualization methods for data derived by the queries. There are three major factors to change the content of dynamic maps, (1) data (unlike conventional geographic systems, we assume that up-to-date data are always used to generate maps), (2) query (a map for a specific purpose is generated by a query), (3) visualization method (even if a set of objects to be displayed is determined, the resulting map cannot be uniquely determined, since we have to distinguish important geographic objects and there is a limit caused by the size of a display). A prototype system GeoProxy was developed in order to prove that the dynamic maps are feasible and useful. This paper also describes the system organization and object management, and presents the demonstrations of interactions with users in GeoProxy.