Lipid-containing Food and specially seafood products are vulnerable to oxidative deterioration, so it is vital to maintain its quality with different ways that are cost-effective. The aim of this study was to produce an antioxidant compound from fish by-product, in order to prevent the disposal of this by-product in the environment and to provide a product that can be used in the food industry. For this purpose, the viscera of common carp (Cyprinus carpio) was hydrolyzed with alcalase enzyme (concentration 1%, temperature 55 ° C and pH 8) at different times including 30, 60, 120 and 180 minutes and their antioxidant activity were compared. The results showed that the protein hydrolysate obtained after 180 minutes of hydrolysis, had significantly higher degree of hydrolysis and better antioxidant performance than 30, 60 and 120 minutes (P <0.05) The highest degree of hydrolysis was 56.66± 0.18%. According to the results of antioxidant activity, IC₅₀ values ​​of DPPH and ABTS radical scavenging power at 180 minutes were 1.34±0.01 and 1.92±0.026 (mg/ml), respectively, and iron reducing power was 0.261±0.01 (OD at 700 nm). Overally, the results showed the protein hydrolysate derived from common carp viscera had antioxidant properties and the hydrolysis time (up to 180 min) affected on degree of hydrolysis and antioxidant properties.