Developing a methodological approach to the definition of the conceptual construct «cluster economy» is extremely important. The meaning of this scientific term represents packed knowledge, experience of the previous studies and searches. Substitution of meaning is a substitution of knowledge. Attempts to define a cluster as an organizational form of economic agents lead to numerous administrative delusions, unpromising expenses on programs of regional cluster development and all-round disappointment. The cluster is not a form, not a format; it is a set of uniform objects, images, communications. Translating the mathematical concept of a cluster into economical terms allows defining a cluster as an active business environment which is formed on the basis of measures of proximity (similarity) of agents of the economic relations. Clustering simplifies generalizing. Clustering in economy reduces transactional expenses. Efforts to clustering the economy «from above» cannot be productive by definition. Clustering in economy is the process «from below» based on development of specialization and comparative advantages of the multitude of agents - entrepreneurs. Clustering of economy, i.e., of business connections, economic relations, agents of the market, is the stage of concentrations of similar entities that correspond to the level of organizational and technological development of the business environment. It is obvious that the stage of the life cycle and the organizational structure are not the same. The consequence of economic systems concentration is the consolidation of elements in the strategic analysis, which simplifies the decision-making scheme, but not the solution. Development of a conceptual framework in the cluster economy theory opens new horizons for researchers, determines the motion vector satisfying the universal principles, allows to use the achievements of scientific thought for designing the future.