The criteria for formation of an inhomogeneous structure based on vitreous Ge 2 S 3 with modifiers Al, Bi, Pb, Te that are identified due to changes in the condensed medium (evaporation temperature, condensation velocity, increasing or decreasing the intensity of the fluctuations of the active field) have been determined. The article analyzes the obtained equations describing formation of inhomogeneous amorphous structures and taking into account the dynamics of the concentration of modifier owing to the source of the atomic flow of a chemical element, structural heterogeneity (availability of vacancies, micropores) and particle diffusion. Computer simulation of the source of the atomic flow of the modifier has been carried out, which makes it possible to form gradient structures with the predicted distribution of the chemical element according to the film thickness. Morphology of gradient structure surfaces and the mechanism of condensation of modifiers Al, Bi, Pb, Te with the amorphous matrix of Ge 2 S 3 have been ascertained.