The article contains an explanation of clusters as a form of economic organization from the perspective of the New Institutional Economics. It have been identified descriptive features of clusters: territorial localization of enterprises, operating in related industries and having dense ties along with reproduction of competition between producers of goods and services - close substitute. It is demonstrated that clusters might be presented as a hybrid form of institutional arrangements. It presuppose combination of resources, implementation of collective adaptation mechanisms, reproduction of competition mechanisms. It has been suggested clusters classification based on three criteria: existence of the core, localization of cluster members ties and mechanisms of clusters evolvement.
Key words: cluster, institutional arrangements, hybrid
JEL codes: B52, D23, L14, L52