The distribution and diversity of marine molluscs were collected in relation to their species richness and
relative abundance in family wise and species wise in different season at five coastal sites in north-east
coast of India during June,2011 to May,2014. A total of 63 species of marine molluscs were recorded, among them
31 species of gastropods belonging to 19 families and 23 genera and 32 species of bivalves belonging to 15 families
and 24 genera .An increase of species density and diversity in the post monsoon season was observed at maximum
selected sites. The maximum density of molluscs fauna was recorded in Bakkhali and Chandipur and highest diversity
was recorded in Digha from selected localities during study period. From these localities is a wide chance of research
to further explore both on the possibility of commercial purpose and ecosystem conservation.