Abstract: Sulfur, nitrogen and carbon residue in the feedstock and products obtained from fixedbed hydrotreating process were analyzed, and the content changes were investigated in this paper. The results showed that most of sulfur and nitrogen in residue feedstock were removed effectively in fixedbed hydrotreating and carbon residue of products decreased considerably. Therefore, the characteristics of the residue feedstock were improved greatly, and the products can be used as an ideal inputs of FCC. With the increase of the reaction temperature, the removal rates of sulfur and nitrogen increased, and a high temperature also helps to decrease the content of carbon residue.