Abstract: Aiming at the phenomenon that the corrosion of overhead circulating reflux of fractionating tower aggravates in processing crude oil with high acid value, new imidazoline amide called EYP was synthesized from oleic acid, diethylene triamine and acetic anhydride. The synthesized compound was characterized by 1H-NMR and FT-IR and the thermostability was investigated by thermogravimetric analysis. The inhibition efficiency of EYP in simulated oil was evaluated by weight loss measurement in comparison with commercially available corrosion inhibitors. Besides, the corrosion morphology of mild steel surface was analyzed by SEM. The results showed that the structure of this compound was correct and that its thermal stability was also good. It had a good inhibition efficiency for A3 mild steel in simulative oil and was a new efficient corrosion inhibitor with high stability and low-cost.