Processes of formation and morphology of crystalline hydrates in cement stone, influence of various factors on formation of morphological forms of ettringite crystals are considered. Influence of ettringite morphology on physical-mechanical and deformation properties of cement stone and role of ettringite in formation and genesis of cement microstructure in various service conditions are shown. For scientific and engineering workers of cement industry enterprises and construction organizations, graduate students, students studying in the specialties "Chemical technology of binding materials" and "Technology of building materials."