By means of gas chromatography-mass spectrometry, information has been obtained on the composition and relative abundance of alkanes; alkenes; steranes; hopanes; mono-, di-, tri-, and tetrasubstituted alkylbenzenes; naphthalene; phenanthrene; and benzo- and dibenzothiophenes in oils isolated from the products of aquathermolysis of high-sulfur natural asphaltite in a flow reactor in the temperature range of 200-575A degrees C.