The article presents the direction of development of the scientific and practical foundations of the technology of cement concretes associated with the use of organic mineral additives. It allows to improve the physical and mechanical characteristics of products and structures. The purpose of research is determination of the mechanism of act organic-mineral additives including reductants of the various physical and chemical nature and an experimental estimation of their effect on a mineral phase structure and properties of cement system. Organic mineral additives are applied in studies for which new options of components of the various physical and chemical nature are observed and received. The study of possible mechanisms of effect organic mineral additives conducted on a water-cement paste and on concreting cement system with roent-gen-phase analysis application are made. The effect of organic mineral additives on properties watering out and concreting cement systems is established. The effect of organic mineral additives including reduct-ants of the various physical and chemical nature, on a modification of a mineral phase structure of growths in the course of a hydration solidification and set strength is determined. The data obtained allow to broaden the understanding of organic-mineral additives effect on a structure and properties of cement sys-tem and to suggest accessible raw reductants in new effective organic mineral additives for obtaining of cement concretes with improved physical-mechanical performances.