The relevance of the research is caused by the importance of accumulation and classification of data on content and composition of nitrogenous components in highly paraffinic oils. The data obtained could help in developing high technologies of their production, transportation, and processing. The main aim of the study is to determine the characteristics of distribution and composition of high- and low-molecular nitrogenous compounds in hard wax-rich oils. The methods used in the study: analyzes of elemental and functional composition, sulfuric acid extraction, liquid-adsorption chromatography over modified sorbents, infrared spectroscopy, nuclear magnetic resonance spectroscopy, and gas chromatography-mass spectrometry. The results. The authors have studied the distribution and composition of high- and low molecular nitrogenous bases in high paraffinic oils with different content of paraffin wax, resin-asphaltene substances, and basic nitrogen. It was determined that there are low- and high-molecular bases with weakly and strongly developed alkyl substitution in highly paraffinic oils. The similarities and differences in composition and distribution of nitrogenous bases in oils with high and low paraffin content were revealed. The bases of highly paraffinic oils are characterized by prevalence of highly alkylated structures. It is shown that the values of structural characteristics of high- and low-molecular nitrogenous bases in oils with high and low paraffin content are similar. Middle molecules of high-molecular low-alkylated bases enriched with aromatic (4-9) and saturated (8-13) rings contain, preferably, 4-5 methyl substituents. The number of aromatic (3-5) and saturated (4-5) rings is lower in high-alkylated bases, which contain 19-38 alkyl carbon atoms distributed to 4-5 substituents with a chain length of more than 4 carbon atoms. Low molecular nitrogenous bases in samples of oils with high and low paraffin content are represented by С[3]-С[8] quinolines, С[1]-С[6] benzoquinolines, С[1]-С[6] dibenzoquinolines, and С[1]-С[6] azapyrenes.