This work investigates the effects of lubricant sulfur contents on the morphology,nanostmcture,size distribution and elemental composition of diesel exhaust particle on a light-duty diesel engine.Three kinds of lubricant (LS-oil,MS-oil and HS-oil,all of which have different sulfur contents:0.182％,0.583％ and 1.06％,respectively) were used in this study.The morphologies and nanostructures of exhaust particles were analyzed using high-resolution transmission electron microscopy (TEM).Size distributions of primary particles were determined through advanced image-processing software.Elemental compositions of exhaust particles were obtained through X-ray energy dispersive spectroscopy (EDS).Results show that as lubricant sulfur contents increase,the macroscopic structure of diesel exhaust particles t from chain-like to a more complex agglomerate.The inner cores of the core-shell structure belonging to these primary particles change little;the shell thickness decreases,and the spacing of carbon layer gradually descends,and amorphous materials that attached onto outer carbon layer of primary particles increase.Size distributions of primary particles present a unimodal and normal distribution,and higher sulfur contents lead to larger size primary particles.The sulfur content in lubricants directly affects the chemical composition in the particles.The content of C (carbon) decreases as sulfur increases in the lubricants,while the contents of O (oxygen),S (sulfur) and trace elements (including S,Si (silicon),Fe (ferrum),P (phosphorus),Ca (calcium),Zn (zinc),Mg (magnesium),Cl (chlorine) and Ni (nickel)) all increase in particles.