Presented article contains information on the research performed in the period 2010-2012, on the quality of the Raut river in its middle part (Bălţi – Floreşti – Brânzenii Noi). The results of the study indicate that water of the river can be characterised as a moderate polluted in the Floreşti raion. Main sources of pollution of the river are: industrial enterprices located on the river banks, unathorised and unmaintenend dumps, animal breeding minicomplex farms, including poultry ones, soil processing, lack of protected green belts (trees, bushes, multiannula grass), which couldwater ecosystems from pollution and siltation.