Influence of the WC/Ni-Cr additive on the cracking of maltenes of naphthenic crude oil from the Usa oil field has been studied. Maltene cracking was carried out at 450 degrees C for 2 h in the isothermal mode. Material balance of cracking, the composition of gaseous products, and the fractional, component, and hydrocarbon compositions of feed maltenes and liquid products of their cracking have been determined. It has been shown that cracking with WC/Ni-Cr gives more gaseous and solid products. In comparison with starting maltenes and the product of their cracking in the absence of the additive, the yield of IBP-360 degrees C distillate fractions increases by factors of 1.6 and 1.4, respectively. It has been found that cracking reactions lead to degradation of resinous components to give low-molecular-weight resins and light hydrocarbons and parallel condensation reactions promote the formation of asphaltenes and solid products. It has been shown that the additive WC/Ni-Cr has cracking properties, as indicated by significant differences in fractional and hydrocarbon compositions of liquid products, and by the fact that the amount of H-2 and C-1-C-2 hydrocarbon gases in the products of cracking is much higher in the presence than in the absence of WC/Ni-Cr. This difference can be due to degradation of not only resins, but also high-molecular-weight naphthenoaromatic hydrocarbons.