To evaluate the effects of dietary vitamin C on the growth performance of common carp and indices of blood hematology, intestine, and liver histology (Cyprinus Carpio), a 60-day study was conducted in well water using 3 experimental treatments (3 replicates per treatment). Three similar diets (isonitrogenous (300 g/kg crude protein) and isoenergetic (13 MJ/kg gross energy)) were formulated as follows: control diet (T₀)without vitamin added, 100 mg of vitamin C, 200 mg of vitamin C / kg diet were supplemented for T₁ and T₂, diets,  respectively. Each diet was fed to triplicate groups of carp with an initial body weight of 2.03g ± 0.02g in 90-L tanks at a stock king density rate of 30 fish /tank. The results showed that the groups fed with vitamin C-supplemented diets recorded a higher final weight, weight gain (WG), specific growth rate (SGR), and an improving feed conversion ratio (FCR) compared to the control group (T_0, p < 0.05). Regarding hematological parameters indices, white blood cell (WBC), red blood cell (RBC), hematocrit (Ht), haemoglobin (Hb), lymphocyte, platelets count and immunoglobulin (IgM) concentrations were significantly higher in fish-fed T₂ diet than other groups. In terms of the normal cellular structure, intestinal villi heights, goblet cell counts, and infiltrating leukocytes, all treatment groups outperformed the control group in intestinal histology. While liver and intestine tissues were less damaged with the increase of vitamin C concentration in the diet. Our findings demonstrate that common carp diets supplemented with 200 mg of vitamin C per kg of feed help enhance growth performance, improve the structure of the intestinal mucosal epithelium, and have a positive impact on the hematological parameter (Cyprinus Carpio).