Mechanical activation is considered today as one of the methods to modify the structure and properties of materials. Mechanical treatment not only allows reducing the particle size to nano-scale, and thus significantly increasing the surface area of the material, but also may lead to formation of structural defects, porosity, metastable crystalline and amorphous phases, to an increase in reactivity and catalytic activity of materials and others [1-3]. In some systems, chemical reactions proceeds under external mechanical impact, which were called mechanochemical effects. When choosing the conditions of mechanical activation (activator type, size and quantity of grinding balls, the material sets, the processing mode, load, environment) a supplement to the material, able to dramatically change the mechanism of mechanical activation, provides a wide field of research. In this work, the structural changes of Mn02, Fe203 and graphite under separate and joint mechanical activation in high-energy planetary ball mill have been studied.