Biomass and nutrient concentrations (mg/g) in plant communities in four major lakes which situated in Northern Black Sea Region of Turkey were examined. Biomass values were significantly changed some of the plant communities in studied lakes, however, there were no significant differences between plant communities in respect to biomass in some lakes. Most of the plant communities in studied lakes were N- and K-deficient. There were significant differences between plant communities even in same communities in different lakes. Water parameters were usually significantly changed from spring to fall.