Background. Theoretical development of the extraction process is an important task for further modeling and calculation of optimal conditions for extraction of biologically active compounds from the plant raw material. The aim of the study was to propose and test a theoretical model to describe the process of Licuroside and Glycyram distribution between the solid phase of Glycyrrhiza radices and the extractant. Materials and methods. For studies, we used Glycyrrhiza radices (Liquorice roots). For extraction, we used plant raw material with particle size of 0.1-0.5 mm, and ethanol-water solution 70 % v/v was used as an extractant. Qualitative and quantitative analyses of biologically active compounds were carried out with standard substances Licuroside and monoammonium glycyrrhizate and according to UV-spectra and retention times of compounds in the HPLC profile. The extraction process was carried out at temperatures of 4, 20, 40 and 60±1 ºС. To construct the simplest mathematical model of BAS distribution between the extractant and plant raw material matrix, we used the law of conservation of matter and the Henry’s adsorption law. Results. Results of these studies demonstrate that the suggested simplified model of the phytocompound distribution process between the extractant and the plant raw material matrix based on adsorption concept can be used to describe the equilibrium extraction process. The mathematical model obtained can be also used for optimization of the phytocompounds extraction process from the plant raw material within the conditions of equilibrium attained in the extraction system. Conclusion. The process of Licuroside and Glycyram distribution in the system Glycyrrhizae radices / ethanol 70 % v/v has been studied. A simplified mathematical model to describe the equilibrium distribution process of these phytocompounds in the extraction system has been suggested. The values of constants in the model suggested have been calculated.