The main achievements of 40 years of research in mineralogy of soils in Moldova were summarized. There were shown the relationship between the mineralogical composition of soils and rocks and their granulometric and chemical composition, the predictability of physico-chemical and physical properties, resistance to erosion and other indicators. There was characterized a substantial role of mineralogical studies in the knowledge of origin of soils and soil-forming material of Moldova, the characteristics of their composition and granulometric geography, in the knowledge of the consequences of the effects of hypergenic processes in establishing the age of soils and weathering crusts. There were highlighted the features and ways of transformation of the mineralogical composition of chernozems, forest and azonal soils under the infl uence of soil formation processes, as well as for use in agriculture. There were described the effects of irrigation on the mineralogy and soil properties and evaluated natural reserves of potassium-containing minerals and potassium in them. The progress in the mineralogical mapping of soils in Moldova was marked.