Analysis of pond water and sediment as well as skin and intestine of common carp, cultured under polycultre system, was done quantitatively and qualitatively. During the study of 60 days (winter and summer seasons), total viable counts of bacteria were in the range of 4.43±0.50x10 3 to 5.5 ±0.09x10 3 cfu g -1 and 7.43±0.03x10 3 to 9.66±0.09x10 3 cfu g -10 6 cfu g -1 respectively for all 3 replicates. In total, 10 bacterial genera and 13 dominant species were identified. The bacteria of pond water and sediment reflected the bacterial composition in skin, gill and intestine of the fish. In the pond water, Corynebacterium spp., Aeromonas hydrophila, Pseudomonas spp., Achromobacter sp. and Flavobacter spp. were predominant whereas in pond sediment, Aeromonas hydrophila, Pseudomonas spp., Corynebacterium sp., Flavobacter spp. and Bacillus sp. were predominant and Corynebacterium spp., Aeromonas hydrophila, Flavobacter spp. and Pseudomonas spp. were predominant in skin, gills and intestine of common carp. During the experimental period, Pseudomonas aeruginosa, Aeromonas hydrophila, Flavobacter devorans and Corynebacterium sp. were predominantly present in all the samples in all the phases.