ABSTRACT: The “Karolinka – sklárny landslide” has been under observation by a combination of complex of geophysical, engineering geological and hydrogeochemical methods since 1977. Due to the long – term monitoring, there is a large number of measured data which are appropriate for another processing and there is possibility of correlation of monitoring and evaluation methods. Therefore this landslide is an appropriate object for observation of possibilities of cluster analyses usage for monitoring of connection between groundwater in the landslide area and surface water in Karolinka reservoir. By the usage of cluster analysis was proved the presence of groundwater in the landslide with chemical composition similar to chemical composition of water from the reservoir Karolinka.