Abstract – this paper continues the authors’ former research. It is focused on modelling adapting device. The equations used for self-tuning or adaptive systems are adjusted to derive the mathematical model of an adaptronic system and the structural scheme of such system is built based on the scheme of self-tuning system. Adapter is described as open-loop automatic control system with two first-order aperiodic blocks and PI controller. As here the main attention is paid to the adapter and to simplify equations, blocks of the main loops are proportional (P) controllers. This is used to make a simulated computer model for adaptronic system