The article is aimed on investigation of expediency of division of combinations of entities on contract-based and statutory. In the introduction the urgency of the topic of the research is disclosed. In the author’s opinion, it is determined by the lack of clearness of the criteria of division of combinations of entities into organizational-legal forms in the legislation of Ukraine. The necessity of their determination is explained by the importance of organizational-legal form of legal entity in the practical activity of the last. The author investigates the role of constitutional documents of combinations of entities in the frame of their division into contract-based and statutory. Therewith it is noted that the legislation of Ukraine does not contain clear list of constitutional documents that are necessary for the establishment and further activity of each kind of combinations of entities. In the article opinions of scientists and judicial bodies on the legal nature of statute are analyzed and author’s own opinion on this question is given. In the summary proposals regarding improvement of legislation of Ukraine that regulates establishment and activity of contract-based combination of entities are expressed.