Synopsis Mangrove is a common term applied to a community of tress or shrubs which grow in the sea. It may be any one individual species which constitutes that association. Mangrove ecosystem is a very specialized environment occurring in between land and sea in the tropical and subtropical regions. Mangrove plants are specially adapted to thrive the various salinity, recurrent tidal inundation and periodic desiccation. This ecosystem besides protecting the coastal line, by their typical root structures, support fishery, by developing a detritus based food web and help in regulating regional climate. Since this system is located in between sea and land, it includes several distinct habitats in terrestrial, intertidal and aquatic environment i.e. dominant forests. Litter laden floor, tidal flat and continuous water causes by rivers, tidal creeks and channels, backwater neritic inlet and bays. It is the natural abode of many a group of animals and large number of species are known to feed, breed and take shelter in this ecosystem....this work is based on intensive studies made by the author for the last 12-15 years from this area. A total account of 56 species of molluscs including 31 gastropods and 25 bivalves along with their common name, ecological notes, distribution, economic uses in respect of each species as far as possible have been given. Keys have also been provided for families, genera and species where ever more than one taxa are included.