The object of this study was to detect the bacterial species that founded in infected common carps Cyprinus carpio in semi-closed systems in two districts of Basrah province. Bacterial gill disease, skin ulcer disease and intestine inflammatory disease were recorded. In the present study, Aeromonas sobria (38.46) was the predominant species, followed by Citrobacter freundii (29.23), Vibrio cholerae (21.53) and Serratia fonticola (10.76%). Identification of the isolates was carried out depending on the morphology of colony, specific media and identification using VITEK 2 system (Biomerieux- USA). Five antibiotic discs were used for antibiotic sensitivity test by the disk diffusion method. A. sobria was sensitive to Nitrofurantion, V.  cholerae was sensitive to Ampicillin, C. freundii was resistance for all antibiotics while S. fonticola was sensitive to Gentamicin. This study represented the first investigation in Iraq on bacterial isolates from semi- closed system.