Recently, ecological water monitoring has become one of the fundamental issues of stream ecology. Out of biotic communities living around streams, macroinverte-brates are commonly used as water quality indicators. In this research, quantitative distributions of macroinvertebrate groups, living on a stream in the Belgrad Forest which represents a status close to the natural one and thus becomes a reference field with this property, were determined and it was explained how the change observed in the hydrological/hydrochemical conditions caused population interaction on the species. Relationships between macroinvertebrate species and environmental hydrological/hydrochemical parameters were established through Canonical Correlation Analysis. It was found that there were strong relationships between Heptagenia sulphurea species and dissolved oxygen amount as well as Potamon fluvitilis and organic substance amount. It was also detected that population of Gammurus pulex increased under conditions with increasing magnesium, nitrate nitrogen amounts and flow- rates.