The objective of this study was to evaluate the soil aggregation and water aggregate stability of Luvisols developed from moraine loams. The soils were classified in various complexes of agricultural suitability: very good wheat (first), good wheat (second) and deficient wheat (third). Soil samples were taken from Ap horizons (from the depth of 0-25 cm) and from Et, Bt and C genetic horizons (from the depth of 25-50 cm, 50-75 cm i 75-100 cm) after the harvest of winter wheat. The Ap horizons of investigated soils were characterised by a higher content of air-dry aggregates in the 0.25-10 mm diameter range (inclusive of aggregates of 1-5 mm), a lower content of clods >10 mm and a higher content of water-stable soil aggregates in the 0.25-10 mm diameter class, especially 1-10 mm, than the subsoil. The aggregate-size distribution in Ap horizons of soils classified in the first complex was estimated as favourable, and in Ap horizons of soils classified in the second and third complexes was estimated as medium. The aggregate-size distribution in the subsoil was estimated mostly as medium. Aggregate water stability in Ap horizons of soils classified in the first and second complexes was estimated as favourable, and in Ap horizon of soils classified in the third complex was estimated as medium. Aggregate water stability in Et, Bt, BC and C horizons was classified as medium or weak.