The morphology and diameter of Cu and La2O3-Ce2O3 nanoparticles were observed and measured by TEM. The tribological properties of the lubricating oils containing nanoparticles were examined by MRS-1J four-ball tribotester. A 300-hour contrastive experiment was carried out in KDE5000E diesel engine.The results show that lubricating oils containing nanoparticles have optimal tribological properties, when WCu:WLa2O3-Ce2O3=2:1,WCu+ La2O3-Ce2O3=0.8%. Wear values of friction pair using 40CD oil with Cu and La2O3-Ce2O3 nanoparticles decrease by 88.6%-100%,compared with using 40CD oil. The consumptions of diesel oil reduce by 9.29%.