The paper points out the specific challenges of possible appearances, threats, risks and dangers to critical infrastructure caused by the activities of modern terrorism. Sensitivity and protection of networks and systems at the national level is priority for national security and the basics on prevention and coordination of measures and activities between the security services. Modern terrorism knows no borders, regions, states. It is focused on critical infrastructure, whose damage or destruction accelerates the motivation for achieving goals. Targets are: pipelines, telecommunications, information technology, financial systems, social, economic, industrial, medical and other important segments of the society, where important preventive roles have not only national, but also international actors and institutions, the European Union, NATO, OSCE, INTERPOL. The new millenium has shown that there is no country that is completely safe and protected from modern forms of asymmetrical threats. The World is “bombarded” with information on a daily basis about events that create feelings of insecurity, fear, threat and danger. Critical infrastructure have become the target of new forms of terrorist threats, known as cyber-terrorism, bio-terrorism, eco-terrorism, nuclear-terrorism and others. This suggests opportunities and the increasing effects of terrorist threats that are more difficultly controlled and managed. Republic of Macedonia follows the efforts of the international community in preventing and countering activities of modern terrorism. Besides participation in NATO operations for the establishment and provision of peace and security in crisis regions worldwide, national security structures have an important role in protecting national critical infrastructure. Contemporary aspects of prevention and protection in society are the basis for establishing, monitoring, detecting, preventing and managing the potential threats directed against critical infrastructure. Besides this, the paper contributes to defining the measures, activities and functions of state authorities in preventive action and combating modern terrorism aimed at social goods, critical infrastructure and security of society as a whole.