The study on the structure of benthic macroinvertebrate communities took place in the Lower MureÈ defile (May 2011, 18 sampling points). Following the processing of benthos samples, 20485 individuals were identified, belonging to 14 groups of benthic macroinvertebrates.In all sampling points the clean water indicator groups (Amphipoda, Efemeroptera, Plecoptera, Trichoptera) registered a high abundance.