Cladocerans are very promising for studying climate change risks owing to their inherently predictive nature. For paleoecological study, one sediment core (17-Ya-01) was sampled from lake in Yamalo-Nenets Autonomous Okrug (Russia). Cladoceran analysis of the sediment core with a length of 51 cm collected from the studied lake is performed. A total of 30 taxa were registered in the subfossil cladoceran community of the lake. Most of the identified taxa belong to the Chydoridae family. Bosmina (Eubosmina) longispina was the dominant species. Of special interest is the finding of Ophryoxus gracilis and Rhynchotalona latens - rare species.