Zooplankton community transformation in response to soft water acidification was studied in two experimental series using the microcosm method. The dynamics of total abundance, changes in the proportions of the main zooplankton groups, stability of the dominant complex, and species diversity were evaluated. Zooplankton population proved to decrease at all studied low pH (5-6, 4-5, and 3-4) within the first two weeks relative to the control. At water pH 5-6, either Rotifera-Copepoda or Cladocera-Copepoda zooplankton complex was established depending on the initial community composition; while at pH 4-5, Copepoda predominated in the established zooplankton community. The community edificator species was replaced at pH 4-5. The lowest diversity index was also observed at this pH (1.0-1.5 bit/ind.). In addition, the proportion and absolute population of copepod nauplii and cladoceran Scapholeberis mucronata increased at low pH. A decrease in water pH to 3-4 proved to be disruptive for the zooplankton community.