Calcutta is sustained by unique and friendly water regime. To its West flows the river Hooghly, along the levee of which the city has grown. About 30 km eastwards flows the river Kulti-Bidyadhari that carries the drainage to the Bay of Bengal. Finally and central to this regime is vast wetland area beyond the Easter edge of the city that has been transformed to use city waste water in fisheries, vegetable gardens and paddy fields in the successive tracts of land. In the year 2002 East Kolkata wetlands has been recognized a wetlands of international significance to understand the concept of ‘wise use’. In the past it was a rich abode of wildness and was well known for its rich floral and faunal diversity. The paper mainly discuss about understanding the state of wetland habitat using water bird as the biological indicator. Living organisms are sensitive to the changes in the state of their environment. The changes in their abundance are used to analyze the state of the environment in the study area. Monitoring the presence, abundance as well as nature of birds species in the study area not only tells as about the current state of an environment but repeated monitoring should a drastic change in this wetland ecosystem.