The growing complexity of the security environment has recently revived systems theories in many areas. Yet, the notion of security system has been used in strategic documents of the central European countries already for many years.
This paper thus examines how the understanding of the security system has developed over time in Poland and the Czech Republic and how do the national concepts of security system relate to the theoretical understanding of systems. Finally, we examine how the idea of security system is translated into practice in the two countries.