The relevance of the investigation is caused by the need to obtain new data on the high-molecular heteroatomic components of oil feedstock supplied to the refineries. Accumulation and generalization of information on composition and structure of resins and asphaltenes are important for the development of advanced technologies of deep processing of hydrocarbon raw materials and measures for environmental safety of oil refineries. The main aim of the research is to study structural-group characteristics of components of oil treated with different metal-containing powders. The methods used in the study: elemental analysis, cryoscopy in benzene, PMR-spectroscopy, structural-group analysis. The results: It was found out that introduction of copper- and iron-based powders, modified with the ions of bivalent nickel and cobalt, into the oil system results in changes in structural-group characteristics of asphaltene and resin molecules. Joint presence of bivalent nickel and cobalt ions in the treating reagent has the main influence on the changes in the structural-group characteristics in resinasphaltene substances occurring in oil. After the treatment with the given powder one can observe in asphaltenes typical decrease in average molecular weight, sulfur and nitrogen contents, total number of carbon atoms in a middle molecule, total cyclicity of structural units, due to reduced number of naphthenic cycles, and increased number of carbon atoms in the alkyl substitution. As compared with the resin-asphaltene substances of the initial oil, the resins after the treatment with the metal powders are characterized by increased average molecular weight, reduced sulfur content, increased total number of carbon atoms in the middle molecule and total cyclicity of structural units due to increased number of naphthenic cycles, and reduced number of carbon atoms in the alkyl substitution.