The article presents the actual problem of studying the career self-determination of a proactive personality. The problem of proactive career building is revealed in modern scientific domestic and foreign studies through such basic psychological concepts as potential, strategy, orientation, skills. The personal and organizational determinants of the implementation of a proactive career are analyzed. In this study, the universal characteristics of career proactivity are highlighted, and it is also shown that the system-forming property of career activity in the VUC environment is proactivity as an integral property of personality. In the paradigm of the system approach, the authors proposed a proactive career model for the VC environment, which includes three main components: value-motivational, strategic and competence. The integral nature of proactivity ensures relationship between these components of the career activity system, penetrating and filling each of them with content.