The paper presents data on sapropels from ten lacustrine systems at the Barabinsk and Kulunda plains in Novosibirsk region. The sapropels are classified according to the type of the biological contribution to their origin and the content of organic matter. The sapropel of lakes Kachkulnya and Barchin, which are rich in organic matter and differ by the type of their origin (macrophytogenic and planktonogenic), were studied in much detail with the application of the following techniques: X-ray diffraction (XRD), atomic absorption spectroscopy (AAS), and elemental (CHNSO) analysis. Groups of organic compounds contained in the organic matter were determined by successive extraction, and the monosaccharide composition was studied by high-performance liquid chromatography (HPLC). The organic matter of sapropel with different type of boilogical contribution was discovered to differ in elemental (CHNSO) composition, group of organics, and the monosaccharide compositions. Our results led us to conclude that the genesis of sapropel significnalty imprints the composition of its organic matter.