Abstract: Lowering sulfur contents in fuel oil,which is al-ready below50μg /g in many countries and regions,is an important measure to reduce pollutant emission in end gas and to protect environment.The lubricating properties of diesel oil get poorer along with the reduction of sulfur content.Low-sulfur diesel oil can enlarge the attrition rate of engines and even can result in engines out of function.This paper analyzes the ways to improve the lu-bricating properties,introduces the experimental process and results of the impacts of three additives on lubricat-ing properties,and points out that adding additives is an effective way to enhance the lubricating properties of diesel oil.