The investigation of the influence of environmental factors on rotifers and selected species of planktonic diatoms, and green algae were carried out in the three submountane reservoirs: Czorsztyn (CR), Dobczyce (DR) and Rożnów (RR). All reservoirs are located in southern Poland. All three reservoirs are submountane type, but they differ in trophic state, age, shape, depth etc. In these studies, the most abundant species from rotifers, diatoms and green algae were chosen. Additionally, the physico-chemical parameters were used in the statistical analyses. RDA analysis showed effect of environmental factors on rotifer communities but did not show any affect on the chosen algal species. The most important environmental factors which had influence on rotifers were water temperature, Ca and alkalinity. The following study proves that each type of reservoir contained a variety of rotifer communities, with changes in species composition occurring in relation to changes in environmental conditions.