ABSTRACT Aeromonas infections are regarded as the most common bacterial infections in fresh water fish and fish suffering due to aeromoniasis show external symptoms like hemorrhages at the base of fins or on the skin, distended abdomen and protruding eyes. Labeo rohita, one of the most important freshwater Indian major carp is selected to understand the pathogenic effects of Aeromonas liquefaciens. Five groups of experimental fish (65-75 gm wt) were employed in this work. 12 fish in each group were infected intramuscularly @ 10-2 CFU/Fish (group A), 10-4 CFU/Fish (group B), 10-6 CFU/Fish (group C), 10-2 + 10-2 CFU/Fish (group D) and 10-3+10-3 CFU/Fish (group E);12 fish were kept as uninfected control ( group F) for comparison. Six fish from each infected group and controls were necropsies at hour 24 and 96 tissues of muscle and head kidney were separated and analyzed for protein profile by SDS-PAGE analysis. 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