The abundance and factors affecting the population characteristics of waders in Great Vedaranyam Swamp was studied during 2007-2010. This wetland is a Ramsar site and an Important Bird Area. This habitat attracted 30 wader species, which are local and migratory bird species. Highest population of Greater Flamingo Phoenicopterus ruber was recorded in all the years of study period. The physico-chemical parameters such as calcium, chloride, dissolved oxygen, electrical conduc- tivity, magnesium, nitrate, nitrite, pH, phosphate, total dissolved solids, salinity, sulphate, turbidity, water depth and water temperature have been tested. The physico-chemical parameters were compared with the small and large waders density (birds / km 2 ) and diversity (H'). The multiple regression models were made to evaluate the relationship between the phys- ico-chemical parameters and waders population characteristics. Such a water quality parameters showed significant varia- tions among the variables. The abundance of phyto and zooplankton, polycheates, gastropods and decapods, the prey items of the bird were also compared with water quality parameters that showed significant variations. The result suggests that physico-chemical parameters of water as a vital role to regulate the bird community and their prey items.