Chemolysis of ether/ester and sulfide bonds in the molecules of high- and low-molecular-weight asphaltenes of heavy crude oil from the Usa oil field has been performed, and the composition of the liquid products of their cleavage has been studied. It was found that the core of the molecules of both fractions of asphaltenes is bound with alkanes, cycloalkanes, aromatic hydrocarbons, and heteroatomic organic compounds via ether/ester and sulfide bridges. High-molecular-weight asphaltenes of oil from the Usa oil field are characterized by a higher proportion of "sulfur-bound" structural elements. Compounds bound by ether/ester groups contribute substantially to the structure of the low-molecular-weight asphaltenes.