The paper presents the results of research on the use of the basic provisions of andragogy to improve modern systems of training professionals in a particular professional field (information security). To do this, the characteristics of such systems were determined, the classification of trainees according to the criteria of adulthood was carried out, the possibilities of applying the basic provisions of andragogy to the object (an educational system) and the subject (processes, methods, and technologies of training) of research in the selected area were considered.