The paper presents the results of investigation of changes in the composition of hydrocarbons and sulfur-containing compounds of an atmospheric residue in the course of cracking in the presence of a tungsten carbide-nickel--chromium (WC/Ni-Cr) catalytic additive and without it.The cracking is carried out in an autoclave at 500 ℃ for 30 min.The addition of the WC/Ni-Cr additive promotes the deepening of reactions of destruction not only of resins and asphaltenes,but also high molecular weight naphthene-aromatic compounds of the atmospheric residue.It is shown that the content of low molecular weight C9-C17 n-alkanes and C9-C10 alkylbenzenes rose sharply in the products of cracking with addition of WC/Ni-Cr in comparison with those produced without the additive.Alkyl-and naphthene-substituted aromatic hydrocarbons of benzene,naphthalene,phenanthrene series,polyarenes,benzo-and dibenzothiophenes are identified.