Abstract: Assemblage of fish and their seasonal variation in two floodplain lakes in the Bongaon subdivision of the north 24-parganas district of West Bengal in India was investigated during the period 2004 to 2006. These lakes are locally called as baur. Forty nine species belonging to 23 families were recorded from these two baurs. Cyprinidae was the most dominant family with eleven species. Overall species composition of the two baurs almost resembled each other. But average number of species in a month significantly varied between the baurs. Species richness and the total number of individuals caught per each sampling varied significantly between seasons. Amblypharyngodon mola (Cyprinidae) and Gudusia chapra (Clupeidae) were the most abundant among the eighteen frequently available species from these two baurs. But more than fifty percent of the species were sparsely available.