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Aeromonas hydrophila is an opportunist pathogen in fish and responsible for wide range of fish diseases. In this study, the effect of different levels of curcumin in the diet on growth and resistance to infection with Aeromonas hydrophila in common carp (Cyprinus carpio) was investigated by peritoneal injection. For this purpose, six concentrations of 0.2, 0.4, 0.6, 0.8 and 1% of different levels of curcumin were mixed with a special feed for carp. 360 common carp with an average weight of 50±4/7 g (divided into six groups), each group was divided into 60 fish and 20 fish per replication. Live Aeromonas hydrophila was exposed to concentrations containing Cfu/ml10 of Aeromonas hydrophila for 10 days and post-challenge mortality was compared between treatments.The results showed that administration of 0.8 and 1% curcumin caused a significant increase In the reduction of losses after challenge with Aeromonas hydrophilis in bacteria in treatments of 0.8 and 1% curcumin showed significant compared to the control treatment (p <0.05).In general, it can be said that the most appropriate concentration of curcumin in feed to increase resistance to infection Bacterial cells are 0.8 and 1%.