Cartographic generalization in geological mapping is receiving increasing interest, though only few reliable automated generalization tools are available for this purpose today. Thus, improvements to methods for the generalization of categorical data, such as geological or soil maps are in demand. Weadvocate a constraint-based approach for geological map generalization, which could be implemented by integrating vector and raster based generalization methods. The research is divided into three parts: conceptual development, process modelling and data processing,and vector and raster based geological map generalization. In the first part, wedevelop the general methodology of the research, including identification and classification of constraints for geological map generalization, whilethe second part is dedicated to process modelling and its implementation. The thirdpart of the research evaluates the results of generalization while comparing advantages and drawbacks of vector-based generalization against raster-based generalization. Below wegive a short summary of the overall research idea highlighting the gaps found, methods used and some initial results.