Seasonal variation of the plankton population with sediment analysis in a freshwater pond at Coimbatore was carried out during 2010 to 2012. Nine species of algae were identified in the sulur pond. Among them six species were belonging to bacillariophyceae, two species belong tochlerophyceae and one species belong to myxcophyceae. All these species were found in stations identification was rare. Four species of crustaceans namely, herpatacoid Sp., Diaptomus Sp., Naupliulervacyclops Sp and Daphnia were identified. Three species of aquatic insects were recorded namely aytiscus Sp. Gerris Sp and Hebrus Sp.Totally four species of molluscs were identified namely, Indoplanorlirsexustus, Lamellidensmarginalis, Ballamyadissimilis, Mefania Scabra. Indoplanrlisexustus and Melaniascabra were identified. Four species of fish namely puntiussarana (Hamilton), Catla catla (Hamilton), Cyprinuscarpio and labeo rohita (Hamilton). In present investigation the sedimental characteristics like nutrients and heavy metals polluted to the desirable limits. The pH remains alkaline throughout the course of study. Due to sedimental contamination the nutrient levels are also higher.