The aim of this study was to assess the effect of a gel-forming polymer (Aquanika) added at the doses of 1 and 2 g kg-1 on structure, water and air properties of eroded soil developed from loess. The addition of the hydrogel resulted in a significant reduction in content of clods >10 mm and a significant increase in the content of air-dry aggregates in the 0.25-10 mm range size in the soil surface layer. At the same time, the content of water-stable aggregates in the 0.25-10 mm range size also increased significantly. In the second year after Aquanika application, more of these water-stable aggregates of 0.25 to 10 mm were found only in the plots treated at the dose of 2 g kg-1 as compared to the control plots. The addition of the hydrogel significantly decreased soil bulk density, while increasing actual soil moisture, its maximum water capacity, saturated hydraulic conductivity, total porosity, the content of macropores with diameter >20 m and air permeability in the soil surface layer. Values of Dexter index, S, for the soil from the plots treated with Aquanika were similar to those obtained for the control plots and are indicative of a very high physical quality of the soil.