Plankton takes very important role in the water reservoir ecosystem as part of the food pyramid. In this work was to study and describe the seasonal dynamics of zooplankton at two successive stabilization ponds for wastewater treatment in the village Zbytiny in Bohemia forest. Water from the ponds flows through the stream Zbytinský potok to the river Blanice, which is one of the few places, where is the remnants of the population of critically endangered freshwater pearl mussel Margaritifera margaritifera still surviving. Sampling took place at least once a month. Total was identified and distinguished in determining the abundance of 22 taxa. The aim of this thesis was also more focus on the species composition of the genus Daphnia sp. development and representation of these species during the year. Copepoda group was dominat on both ponds during most of the year, in the rest of the samples without one dominanted rotifers. In the June samples was prevailing gender Keratella sp. and winter samples are divided dominance the genus Brachionus sp. and the genus Polyarthra sp.. Representatives of the Cladocera have an important position especially in samples from early summer (May, June), which corresponded with the clear water phase. If the samples occurred Cladocera representatives, they were mostly the genus Daphnia sp.. The second pond unlike first pond in April samples strongly pushed Daphnia cucculata. In the first half of the year and occurred in samples from May and June was the dominant species Daphnia magna. It then disappeared during the summer and was replaced by smaller species Daphnia galeata. Samples collected in one day on the sampling sites within a single pond was quite different. There was found spatial heterogeneity between this two places. Development model corresponds with models of the plankton succesion mentioned in the literature and communities in these ponds behave like communities to eutrophic reservoirs.