Soils of the Lena River Delta were discussed in terms of  morphology, diversity, main chemical, physical properties and HAs molecular composition. It was shown that the investigated soils are formed under the influence of several soil-forming processes, the processes of cryogenic mass exchange are considered as a main soil formation process, the second most  important process is alluviation and formation of Umbric Cryosol (Fluvic, Arenic, Reductaquic) with pronounced features of soil stratification. Erosion of the floodplain and resedimentation on its surface of suspended particles in the water results in formation of stratified soils, underlain by solums with

well-expressed cryogenic features. Soils of the delta are characterized by high amount of carbon, accumulated in fine earth, and well-expressed formation of  folic horizons in topsoil layers. Texture soil classes were represented by four categories: sand, loamy sand, sandy loam and silt loam. This suggests a large amount of alluvium deposits in the delta and that settling of large particles results from fast river flow. Humic acids of selected soils were investigated in

terms of elemental and structural composition with special reference to evaluation of organic matter stabilization degree and assessment of carbon species distributions in the molecules with use of solid-state 13C-NMR spectroscopy. It was shown that the prevailing of aromatic compounds on the aliphatic one is more pronounced in the Lena River Delta than in other Arctic soils.