Today, due to the growing human need for healthy and quality protein sources, The demand for aquaculture products has increased. Therefore, the use of healthy diets that maintain good health and improve the growth performance of fish during the breeding period is of particular importance. In recent years, the use of various plant additives as boosters of antioxidant systems, immune system and growth stimulants in the aquaculture industry has received more attention. among natural antioxidants, rosemary extract has been found to be rich in antioxidant properties. One of the effective methods on changing some bioactive compounds of plants is irradiated. Irradiation can change the amount of active ingredient in some plant compounds, including compounds that affect antioxidant activity. In the present study, the properties of rosemary dry extract and electron beam rosmary dry extract as an antioxidant stimulant on oxidative stress parameters, growth, nutrition, biochemical and immuno safety factors, hematological parameters and carcass composition of farmed nile tilapia were investigated. The experiment was performed in 39 tanks 80 liter with 13 treatments and 3 replications for each treatment for 60 days. Experimental treatments include 9 diets containing 3 different levels of electron beam (10,20 and 30) KG with different amounts of rosemary dry extract (100,500 and 1000 mg / kg diet), 3 diets with amounts (100,500 and 1000 mg / kg diet containing pure rosemary dry extract, and a control diet (no rosemary dry extract) was performed. The results showed a significant difference in oxidative stress indices, blood serum, biochemical parameters and liver enzymes in the treatment containing 100 mg/kg of rosemary dry extract with 30 KG electron beam with the control treatment (p 0.01). The amount of RBC and Hct underwent the effect of 30 KG electron beam was significant (p?0.05). MCHC content also showed a significant increase in the treatment with 0KG irradiation (rosemary dry extract without electron beam) compared to the control treatment (p 0.01). Hb and MCH levels in the treatment with 0KG electron beam were significantly increased compared to the control treatment (p?0.05). MCV content in treatment with 100 mg/kg rosemary dry extract showed a significant increase compared to control treatment (p?0.05). WBC differential showed a significant difference in all treatments compared to the control treatment (p?0.05). So that the lymphocyte count in 100 mg/kg treatment with 30 KG electron beam was significantly higher than the control treatment (p?0.05). In contrast, the lowest thrombocytes and granulocyte counts were obtained in the treatment with 1000 mg/kg and heterophils in the treatment with 30 KG irradiation (p?0.05). The amount of growth, nutrition and carcass quality parameters in the treatment with 0KG electron beam of rosemary dry extract showed a significant increase compared to the control treatment (p 0.01). Overall, the results of this study showed that the use of rosemary dry extract as well as electron beam rosemary dry extract in the diet of nile tilapia improved the performance of oxidative stress indices, blood and biochemical parameters, growth, nutrition and strengthening the immune system in this fish. In addition, the results showed that the treatments containing electron beam rosemary dry extract were superior to other treatments in many of the studied parameters. Finally, based on the findings of this study, the use of electron beam rosemary dry extract with a concentration of 30 kG at a concentration of 100 mg /kg in the diet of fingerling nile tilapia is recommended. Keywords:Aquaculture, Antioxidant defense, Free radical, Rosemarinic acid, Hetero