The issue of the dimension as a defining value in geopolitical security and its deriviative fields is a fundamental subject determinative to international security. This applies to the regional phenomenons, as well as the global ones. In article the author presents essential notions of the idea of dimension and its genetic origin with its meaningful many reflections. The historical aspects of constitution of its meaning and the most important theories dealing with the practice and abstraction of dimension’s awareness are described. Presented study of dimension phenomenon as aplicable to security studies, as it is argued, extends the realistic evaluation of the world security politics. The author crossectional presentation of the issues in that area presents understanding of a unison between holistic and particular values of the subject discussed