The bottom fauna was studied month-wise during the period April 1963 to March 1964 from 31 sampling stations all over the Chilka Lake. The hydrological conditions, nature of bottom, transparency and vegetation of the lake are discussed in relation to distribution and abundance of benthos. The distribution of animals in different sectors from month to month showed the largest benthic population during October to December and minimum during monsoon period July to September. The microbenthos from the whole lake showed dominance of foraminifers and nematods whereas among macrobenthos molluscs (83%) were dominant followed by polychaete. The mean biomass from the whole lake was 13.57 gm/sq.m and the density 2,720 specimens/sq.m.