The present study was conducted for the isolation, identification and mol. detection of the bacterial flora present in the respiratory tract of apparently healthy 4 breeds (Khaki Campbell, Pekin, Jinding and Muscovy) of ducks. Out of 60, a total of 48 respiratory samples from Bangladesh Agricultural University poultry farm (BAUPF) and 12 from scavenge area were collected. Three bacteria were isolated and identified from samples by cultural, staining biochem. tests and mol. detection. The prevalence of E. coli, Salmonella spp. and Pasteurella spp. of Khaki Campbell duck were 50%, 41.67% & 58.33% and 50%, 50% & 66.67% recorded from BAUPF and scavenging area, resp. Out of 60 samples, the overall prevalence of E. coli, Salmonella spp. and Pasteurella spp. were 50%, 31.67% & 50%. In both sources, E. coli and Pasteurella spp. shown high prevalence in BAUPF and scavenging area. In BAUPF the isolation of E. coli, Slamonella spp. and Pasteurella spp. were 0, 2 & 2 and 2, 0 & 1from both adult and young Khaki Campbell duck. On the other hand, in scavenge area the isolation of E. coli, Slamonella spp. & Pasteurella spp. were 1, 2 & 2 and 2, 1 & 1 from both adult and young Khaki Campbell duck. So it was found that the isolation of bacterial species shown higher in scavenge area than in BAUPF. The highest number of bacteria were recovered from lungs (27 isolates from 8 samples) while the lowest number were from tracheal washing and swab of infraorbital sinus (14 isolates from 8 sample in both cases). Total bacterial isolates were 6 isolates E. coli 3, Salmonella spp. 2 and Pasteurella spp. 2 were found pos. by conventional PCR. The results of this study would be helpful for prevention and control of bacterial respiratory diseases in ducks.