Abstract: Excessive organochlorine in the crude oil is one of the key issues leading to corrosion of refinery equipment. In this paper, the influence of water flooding additives, the injection water and the acidification solutions on the organochlorine content in the crude oil of Jianghan oil producing area in Bamianhe Oilfield has been studied. The chemical reaction pathways leading to the generation of new organochlorine in oils produced from Bamianhe Oilfield has been discussed. Finally, suggestions are made on how to control the use of chemical additives in chlorine-contained oilfield, which can provide a reference on how to avoid the organochlorine exceeding problem in externally-transported crude oil, and in turn to avoid the organochlorine corrosion problem in the downstream refining equipments.