The authors represent a research material describing the specificity of motivation of young specialists during the assimilation period at internal affairs agencies as an important factor in the field of HR management, which is the research subject of this article. According to the research subject, the authors formulate the goal to conduct a psycho-diagnostic research of 150 young employees studying at a subordinate education institution. To detect the peculiarities of motivation, the authors use the following methods: interview, test, and association experiment. For the interview, the authors prepared a set of questions about the reasons for enrolling at law-enforcement agencies. For testing, the authors use the questionnaires «Labor activity motivation structure» and «Diagnostics of motivational structure of a personality». The authors use the method of association experiment to study self-motivation. In the result of the research, the authors arrive at the following conclusions:   Young employees don’t have enough motivation, particularly self-motivation as self-actualization, at the same time they declare external positive motivation as a need for a paid job allowing them to supply their capital needs. It is necessary to form motivation, especially self-motivation, of young employees during their assimilation period as internal affairs officers using such methods as assimilation and motivation training, business simulation, psycho-diagnostics, conversation, discussion, and many others. The scientific novelty of the research consists in the study of external and internal motivation of young officers of internal affairs agencies during their assimilation period, the analysis of peculiarities of manifestation of their external and internal motivation, and the formulation of the ways to form their motivation, particularly self-motivation, promoting the development of their professional skills.