The paper deals with the geochemistry of lanostane homologue molecules, the age and localization of organic matter (OM) enriched in lanostane biomarkers, and organisms synthesizing lanosterol and other lanostane compounds. Steranes of the OM bitumens of the Lower Cambrian Sinyaya Formation on the northern slope of the Aldan syneclise were studied by chromato-mass spectrometry. Lanostanes C30 have been found for the first time in the organic fossil of the Cambrian sedimentary basins, and the presence of norlanostanes C29 is assumed. The sedimentation and diagenesis conditions and the degree of maturity of OM containing lanostane and its derivates are considered. Lanostanes are proposed to use as biomarkers of the petroleum-generating rocks of the Sinyaya Formation for elucidating the source of naphthides in the eastern Siberian Platform.