The article is of current importance in the field of pedagogics and psychology of higher education as it reveals psychological prerequisites for formation of a specialist and his/her productive self-realization as of the subject of activity. The purpose of the paper is to study the features of manifestation of students’ subjectness which ensures success in mastering professional education. The author considers the conception of this phenomenon as a psychological formation and discloses its manifestation through a set of subject actions of a student. The main subject actions include self-actualization and self-control, which provide the quality of the student subjectness manifestation in the process of mastering professional competence. The materials of the present paper can be useful for high school lecturers and students seeking for self-improvement and self-development.