Different sensitivity of benthic macroinvertebrates was used in determining water quality of the eight major tributaries of the Danube, which drains two mountain ranges: Locvei and Almăjului, within the context in which the macrozoobenthic community is influenced by changes in the qualitative parameters of aquatic ecosystems. To get an overview, a series of physical- chemical parameters (water temperature, pH, oxygen, conductivity, cyanide, nitrites, nitrates, phosphates) was studied in parallel with the study of benthic community. Elevated abundance of benthic groups in the case of water quality characteristic (Ephemeroptera, Trichoptera, Plecoptera, Amphipoda), along with their high frequency in all the monitored tributaries in the present study and the water quality parameters maintained within normal limits fits these lotic ecosystems in the A class of surface water quality.