The development of interest in anthocyanins in recent years is associated with an increase in the range of applications of these natural glycosides, contained in plants and berries, the color changes from red to blue with increasing pH. In addition to coloring properties (clay, fabric, hair), the use of anthocyanins – components of red and blue berries (including blueberries) – helps to reduce the risk of cardiovascular disease, Parkinson's disease and more.Most practical studies concern the interaction of anthocyanins with surfaces (clay, tissue, gastrointestinal mucosa, etc.) that have many hydroxyl groups. Therefore, the question of determining the approximate pH range is relevant, in which such an interaction is most likely. The aim of the work was to determine the priority form of the dye (according to the pH of the medium), which can be better fixed on the surface of kaolinSimulation of the interaction of cyanidin with the surface of white clay was performed by the Hartree-Fock-Rutaan method, using the GAMESS software package.The paper presents the results of modeling the interaction of different forms of the anthocyanin model – cyanidin (the content of cyanidin in plants is 50 % of the mass of all types of anthocyanins) in solutions with pH<3 (red – forms of cyanidin), 3<pH7 (blue) with a hydroxylated surface of white clay – kaolin, having different types of hydroxyl groups. The aglycone part of the cyanidin molecule artificially was approached at a distance of approximately 2.5 Å to the surface of kaolin. It was shown, that the quinoid form of cyanidin (violet) was the most active of the three forms, mainly in interaction with the silanol groups of the kaolin surface. The form of cyanidin at pH<3 (red) have the lowest energies of interaction with the surface of kaolin