In this study, total phenolic compounds content of Rosemary were determined after extraction with 80% ethanol. The extract with different concentration of phenolic compounds was then used in 2 model systems in order to explore relationships between phenolic content and antioxidant activity. Results showed great reducing power on potassium ferricyanid for Rosemary ethanolic extract. The scavenging effect of both Rosemary ethanolic extract and BHT on DPPH ranged from 91.34 and 82.9% inhibition for 50 ppm concentration respectively, sure Rosemary showed that effect powerful for this test than BHT in same as concentrations. After that doing this tests upon rosemary extract, concentrated of Rosemary extract with different phenolic concentrations and BHT with one concentration than “batter” (coated the Escolar fish) were able to retard auto oxidation. Samples treated with different concentration of Rosemary and BHT and there are fried in 170? for 5 minutes and then them frozen in -18? and packaged in polyethylene bags, and storage for 5 months in -18?. Results showed that TVB and TMA number in Rosemary treatments were less than BHT samples. Results got by GC system revealed that fatty acids analysis changes for Rosemary treatments lower than BHT samples, because of no changes drastic observed in polyene index and PUFAs/SFAs values for Rosemary treated samples with upper concentration. Results showed that for Peroxide, TBA, Totox and acid values for Rosemary treated with increased to concentration, its decrease to rate of composition of this index. In the sensory evaluation, Results showed that there were lower scores in fried Escolar fish which did not contain any kinds of spices in its coat (control) than other investigated treatments. There was a significant (p 0.01, 0.05) enhancement in sensory attributes which appeared in samples containing Rosemary at concentration 0.1%, 0.2% and 0.3% and BHT at concentration 0.1% and compared to control sample. Generally, samples contained 0.3% Rosemary followed by samples contained 0.2% Rosemary demonstrated the highest scores than the other treatments.