Nowadays, in conditions of transformation in the maritime sector of the country, associated with changes of possession forms, establishment of new eco­nomic rules and overcoming the difficulties encountered in any period of changes, new types of relations for coordination of activities in the maritime domain are de­termined. They are established using a new type of civil-military cooperation in protection of the sea interests of the state, as well as in guaranteeing maritime secu­rity. The maritime critical infrastructure protection system is an instrument for adapting these relations to neutralization of modern threats, as well as for mini­mizing the damage effects during crises. This article proposes a register of the Bul­garian maritime critical infrastructure, which is elaborated taking into consideration principles from the modern civil security concept and the experience of leading na­tions in the area of maritime security.