The graduation thesis describes the transition from the analogue geological maps to a geographic information system and representing the built of geological database on the web. The thesis begins with an overview of the basic geological map of Slovenia at a scale 1 : 100 000, stressing the particularities of the geological data presentation. This is followed by the descripitons of digitalization, vectorization and capture of attribute data on the 24 maps, performed in MicroStation. The obtained graphic and attribute data were processed in the ArcGIS Desktop to built a topological database for the area of Tolmin, which was then transferred to Oracle through the use of ArcSDE. The final database is formed by a layer of lithological units, the layer of tectonic joints and the layer of geological phenomena. The established database is applied in the second part of the thesis as the source data to present a dynamic and interactive web map. This was done by using the ArcIMS application and forming a configuration file in ArcXML language, which determines the transfer and the symbolization of data in the browser. The later gives the user a possibility to perform active data management for instance choosing the shown layers, perform navigation tasks, querying graphic and attribute data, layout saving etc