Methods of chromatography-mass spectrometry, IR spectroscopy, viscometry were used to study structural and mechanical properties of highly paraffinic crude oil processed in high-frequency acoustic field. It was shown that ultrasonic treatment leads to an increase in viscosity, yield stress, viscous flow activation energy and internal fracture energy of dispersion system with an increase in processing time. Proportion of n-alkanes С15Н32–С16Н34 and concentration of aromatic hydrocarbons increase in the composition of dispersed phase of processed crude oil according to chromatography-mass spectrometry.