The products of thermolysis of asphaltenes of Lower Visean natural bitumens mined from different parts of the Voya field in the Timan-Pechora province have been studied. It has been found that the thermolysis of asphaltenes results in generation of alkanes, isoprenanes, alkenes, steranes, and hopanes. Genetic indices determined from the composition of biomarkers identified in the thermolysis products of asphaltenes do not contradict the possible genetic relations of the bitumens under study and Domanik crude oils of the Timan-Pechora province.