Research on the ecology of water mites inflowing water has focused mainly on analysis of factorsdirectly affecting these organisms in the aquatic environ-ment. The hypothesis of this study was that apart fromfactors acting within the aquatic environment, the forma-tion of Hydrachnidia communities in lotic ecosystems mayalso be affected by factors acting in the terrestrial envi-ronment. The analysis was made at three different levels oforganization of the environment: (1) landscape level (sub-catchments, terrestrial environment), (2) macrohabitat level(sampling sites, aquatic environment) and (3) mesohabitatlevel (sampling sub-sites, aquatic environment). Somecorrelation was noted between certain species and somesub-catchment parameters. This may indicate a linkbetween some landscape features (terrestrial environment)and the formation of water mite assemblages in the river.The low percentage for physicochemical parameters toge-ther in explaining the variance in occurrence of species,very low correlations between species and physicochemi-cal parameters and the discrepancy in the grouping of sitesin the case of faunal data and data on the physicochemicalindicates that physicochemical factors had little influenceon water mites. Taking into account all three levels oforganization of the environment analyzed, we can say thatat the landscape level we can find only indirect relation-ships between environmental factors and the fauna inhab-iting the aquatic environment; at the macrohabitat level thedescription of Hydrachnidia is more precise but still of ageneral nature. Only analysis at the mesohabitat level fully explains the specific character of Hydrachnidia assemblages