The influence of carbon nanostructures of chemical company “Arkema” and ultradisperse metallurgical dust on the properties and structure of gypsum matrix has been studied with the help of mechanical tests, X-ray phase and microstructural analyses. The additives are introduced into the gypsum binder both separately and together. When carbon nanotubes are used in the amount of 0.001%, the ordered and dense structure is formed that results in improving mechanical properties up to 80%. The carbon nanostructures act as crystallization centers on the surface of which the homogeneous structure with the increased density of interface surface is formed. The introduction of active metallurgical dust into the gypsum binders with the average size of particles 20-30μm does not allow achieving the substantial improvement of mechanical properties that is explained by the large size of particles. It is found that the introduction of additives into gypsum compositions results in the significant change in the morphology and size of crystals.