Influence of humic acids on soil environment is still subject of scientific discussions. The aim of above studies was to investigate the relationships between selected physicochemical
properties of eleven peaty-muck soils and properties of humic acids isolated from these soils. The following parameters were determined for soils: total and organic carbon, density, ash, humification, and the water absorption index. Humic acids were described by: absorbance at 280 nm, absorbance ratios at 465 and 665 nm, at 260 and 665 nm, elemental composition and atomic ratios: H/C, O/H, O/C, C/N, the degree of internal oxidation, and the content of carboxylic and phenolic groups. Statistical analyses showed that an increase in density, humification, and water absorption indices of soils caused a significant increase in the humic acid parameters: absorbance at 280 nm, the oxygen content, O/H, O/C ratios, internal oxidation degree, and functional groups. Statistically significant negative correlations were found for the same parameters of soils and for the hydrogen and carbon content as well as the H/C ratio of humic acids. The relationships showed that there was a possibility to express the properties of humic acids on the basis of more simple parameters measured for soil and without time-consuming isolation of humic acids.