The article deals with the content of future customs officers' professional training. Such notions as "training", "specialists' professional training", "customs officers' professional training". The article presents an overview of the scientific literature, theoretical analyzes of materials concerning the issues of future customs officers' professional training in the higher educational institutions of Ukraine and the Republic of Poland, still remaining open. The major scientific approaches of leading domestic and foreign scientists to study future customs officers' professional training have been characterized, in particular competence approach, functional approach, instrumental approach, learner-centred approach, axiological approach, historical and systematic-and-comprehensive approaches, theoretical generalization The conception of the research problem in the educational sphere of higher educational institutions has been theoretically generalised. The point of the article is focused on the fact that professional training of future specialists of customs authorities is a process of learning, understanding and specific knowledge, skills and proficiencies of future customs officers who perform the functions of future professional activities, fulfil their functions in accordance with their professional duties during customs service. Also it has been noted that professional training of future customs specialists is caused by personal, practical, functional, historical factors that it is important in the process of understanding this phenomenon and in the research and development processes.