The expansion of existing wetlands, their creation from arable land, and the creation of new salt marsh. India has a wealth of wetland of ecosystems that support diverse and unique habitats, this wetlands provide numerous ecological goods and services but are under tremendous stress due to rapid urbanization, industrialization and agricultural intensification, manifested by the shrinkage in their areal extent decline in the hydrological, economic and ecological functions, they perform, this paper illustrates the role of fresh water wetlands (e.g. lakes, pond, riverine, streams & wet prairies, fens,) Marine wetlands, (an estuary, mangrove swamps, bogs, coral reefs,) common wetlands, are being considered beneficial for good and habitat for wildlife, water quality improvement, constructed wetland, systems (CWS) for wastewater treatment have been proven to be effective, low cost and sustainable alternative for conventional wastewater treatment technologies the CWS generally fall under two categories: subsurface flow system and free water system subsurface flow system are designed to create subsurface flow through a permeable medium. Both types of wetlands treatment system typically constructed in basins or channels with a natural or constructed subsurface barrier to limit seepage the paper reviews the different types of wetlands and different types of constructed wetlands by modification of wetlands.