Abstract. The supposed ice melting process leads to a fundamental change in the geopolitical status of the Arctic region: it is becoming more open to different kinds of maritime activities implementation, including navigation, commercial fishing, mineral and energy resources extraction. Not only the Arctic Five (A5) countries, whose coasts are directly washed by the Arctic Ocean, are interested in their realization, but non-regional states also. The 1982 UN Convention on the Law of the Sea (UNCLOS) gives them such opportunities. According to UNCLOS, the central part of the Arctic Ocean beyond the 200-mile exclusive economic zones (EEZ) of the Arctic countries can be considered as a high seas enclave, with all freedoms of the high seas: of  navigation; of overflight; of  fishing; of scientific research; freedom to lay submarine cables and pipelines; to construct artificial islands and other installations. The high seas are open to all states, whether coastal or land-locked, which have equal rights here. In addition, it should be noted that other countries have a right to carry out certain practical activities associated with three (out of six) freedoms named above: of navigation (with some restrictions under Article 234 of UNCLOS); of overflight; freedom to lay submarine cables and pipelines – within the Arctic states EEZ. The appearance of new Arctic players interested in its spaces and resources is connected with significant increase in risks and threats, primarily non-military. This is largely due to fundamental differences between the Arctic Ocean and other sea areas, such as the Indian or Atlantic Ocean. Among these differences: only five Arctic states are washed by the Arctic Ocean’s waters; shallow depth; small total area; a significant length of the shelf zone; special climate conditions, including ice cap; finally – ecological vulnerability. In this regard, the process of the Arctic region’s opening for different kinds of maritime activities implementation poses a problem of the environmental security, protection and preservation of the marine environment and its biological diversity. Despite the fact that security issues in their traditional interpretation are not under the jurisdiction of the Arctic Council, its primary environmental focus indicates that these issues are directly correlated with the main area of its activities. Anyway, the modern interpretation of the "security" concept includes not only a "military", but also an “environmental” component. For the Arctic states, whose geographical position makes them the first victims of any environmental disaster in the region, the provision of environmental security should be the main priority in their mutual policies. The most effective model for the non-military security threats response in the Arctic is cooperation and coordination between all Arctic states at the regional level. One of the problems in the way is that the Arctic Ocean could not be compared with the Baltic and Mediterranean Seas, to which the Article 123 of the UNCLOS "Cooperation of States Bordering Enclosed or Semi-Enclosed Seas" provides the states' right to “coordinate the management, conservation, exploration and exploitation of the living resources of the sea”, and to “coordinate the implementation of their rights and duties with respect to the protection and preservation of the marine environment”. However, the recent transformation of the international maritime law gives Arctic countries some opportunities in this area. First, the regime of the high seas is becoming less conducive for implementation of specific types of maritime activities. In the future, we can expect that the extent of regulation in this area of the World ocean will be significantly increased. The implementation of the high seas freedoms is largely conditioned by the realization of the tasks to protect and preserve the marine environment and its biodiversity. Second, there is a continuing practice of expanding the authority of coastal states in their jurisdiction zones, especially in the EEZ. Despite the fact that the coastal state is not granted any competence in the field of the EEZ security, the practice of a broad interpretation of the “security” concept includes food, resource and environment security. The enforcement of such security regimes is becoming an increasingly common practice, even though it imposes certain restrictions for third countries’ rights in these sea areas. Finally, the adoption of security measures in the EEZ, on one hand, and at the high sea, on the other, should be recognized interdependent and considered all together. In the near future, the number of potential security threats can be significantly expanded due to the increase in the number of maritime activities participants. In addition to the already existing non-military threats (pollution of the marine environment; illegal, unregulated and unreported fishing), new threats may appear: armed robbery of ships (piracy); acts of terrorism affecting both the shipping and offshore installations (oil and gas platforms); illegal transportation of weapons, including weapons of mass destruction (WMD); illegal transportation of narcotic drugs and psychotropic substances; illegal movement of people by sea, including illegal migration. An effective response to these types of threats requires not only individual efforts of the Arctic Five countries, but also collective security measures. In this regard, in order to create a regional security model, the development of collaboration and cooperation between the Arctic countries is essential.