Uluabat Lake is one of the RAMSAR wetlands and it is under the threat of human activities such as drainage of irrigable lands and industrial, domestic and agricultural pollution. The objective of the current study was to investigate the distribution patterns and composition of the zooplankton (especially rotifers) regarding, the physical and chemical environmental factors. Samples were collected monthly at six different sampling stations of Uluabat Lake from November 2001 to November 2002. It was observed that the composition of zooplankton taxa seasonally changed. Rotifera was dominant in the cold period and Cladocera in the warm period, showing negative relations in their relative abundance. Canonical correspondence analysis as a multivariate ordination technique was applied to investigate relationships between spatial and temporal occurrence patterns of rotifer and physical and chemical environmental factors. Rotifer community displayed strong seasonal dynamics considering, their environmental variables. Rotifer communities were influenced by physical factors such as temperature and Secchi depth, chemical factors such as Na, SO4, Ca and HCO3 and heavy metals such as Cr, Cu, Zn and Pb.