Abstract <p>The regularities of sorption of water-soluble organic matter (WSOM) in the composition of water extracts, obtained from the samples of the horizon H of peaty–podzolic–gleyic soil on kaolinite and muscovite, were studied. The extracts contained different amount of water-soluble <i>C</i>_org, mainly with molecular weights about 20 kDa, represented by mainly hydrophilic compounds, but with different ratios of hydrophobic and hydrophilic components. It was established that the sorption of WSOM components under experimental conditions depends on the concentration of <i>C</i>_org in the extracts, on the ratio of hydrophilic and hydrophobic components, on the ratio of mineral (g): water extract (WE) (mL) and is almost independent of pH. Hydrophobic components of WSOM and aromatic compounds are sorbed to a greater extent on the surface of kaolinite as compared with muscovite. The observed decrease in the sorption of <i>C</i>_org on both minerals when recalculating the sorption per unit area of the external surface in the experiments with a ratio of mineral (g): WE (mL) of 1 : 50 as compared with the ratio of 1 : 10 can indicate both a heterogeneity of the sorption centers on the surface of minerals and competition for these centers between the components of WSOM of the studied water extracts. No significant changes were detected in the curves of molecular weight distribution of the WSOM components after the interaction with kaolinite and muscovite.</p>