The protozoan constitutes the basic food sources of any aquatic ecosystem which supports fish and other aquatic animals. Protozoan diversity is one of the most important ecological parameters in water quality assessment. They are good indicator of the changes in water quality because they are strongly affected by environmental conditions and respond to change in water quality. Protozoa are unicellular, microscopic animals found in all habitats. Present study deals with the free-living protozoa from fresh water body.