A comparative study was conducted to investigate a relationship between concentration of arsenic with protein, lipid, ash and moisture content in Cyprinus carpio, Oncorhynchus mykiss, Aristichthys nobilis, Hypophthalmichthys molitrix, Ctenopharyngodon idella, Scomberomorus commerson, Scomberomorus guttatus and Otolithes ruber. A total of 72 sample of common carp, Bighead carp, silver carp and grass carp fishing from Azadegan fish farming center, Ahvaz; Rainbow trout from Cheshme Dimeh and Scomberomorus commerson, Scomberomorus guttatus and Otolithes ruber caught with gill netfrom Hendijan. Wet-digestion method was performed prior to arsenic determination in the samples. The level of arsenic was measured by atomic absorption spectrophotometer. The results showed that concentration of arsenic in the muscle of fishes was 269.87 ± 20.96 µg/Kg. Moreover, levels of protein, lipid, ash and moisture in the samples were estimated at 19.67±0.78 g/100, 2.45±0.45 g/100, 1.49±0.23 g/100, 78±1.89 g/100, respectively. Results also showed a positive correlation between the accumulation of arsenic in muscle of fishes with levels of protein, lipid, ash and moisture (p