This article deals with some of the problems associated with modern international-legal science as practiced in international relations, namely, the interpretation and determination of the legal nature of IAEA’s acts standards, rules, administrative safety regulations and others). The problems of possible military nuclear activity by some states are very difficult and sophisticated. These problems must be decided in the near future. The role of IAEA in such a modern geopolitical situation concerning the efficiency of the non-proliferation treaty’ regime, is really exclusive. Determining the legal nature of IAEA’s acts, their obligatory or recommendatory character, allows the international community to price the cost of non-proliferation’ perspectives and international security.