In the article the current state of research on the problem of the structure of the system of law and the criteria for distinguishing branches and institutions of law in legal science is being studied. It is noted that in studying this issue it is necessary not only to reproduce traditional approaches in the theory of law, but also
 to take into account the latest developments of domestic theorists of law in this area, critically analyze the possibilities of using them to address ambiguous issues of legal theory. The debatable problem of the criteria for distinguishing branches and institutions of law as structural components of the system of law encourages the continuation of scientific research aimed at an objective solution to this issue. One of such researches is the work “Branches and institutes of the system of law (myths and reality)” (K., 2002) of the author of the dialectical theory of law, Doctor of Law O.I. Yushchyk. The use of the dialectical method as a basic method of scientific knowledge gave him the opportunity to draw fundamentally new conclusions about the structural elements of the system of law that change the traditional legal picture.
 It is determined that the primary structural element of the system of law should be considered not a norm of law, but subjective rights and relevant legal obligations of the subjects of legal relations in their interaction, which are expressed in the disposition of norm of law (subject of norm of law).
 It is noted that the institution of law is not built on the basis of homogeneous social relations of a certain type, but the objective substantive basis of legal institutions are the relevant social institutions, the necessity of which in a particular society is determined by social needs. Norms of law regulate social relationships, primarily through the legal regulation of relevant social institutions. The formation of a legal institution in the system of law means that the relevant social institution is recognized by the government as necessary, mandatory, that is, it is sanctioned by it, and therefore the rules of conduct that determine the functioning of this social institution are embodied in norms of law.
 It is stated that the basis for building a branch of law is not a common subject and method of legal regulation, but generalized (generic) starting law, which includes a range of starting rights (subjects of norms of law, their dispositions, ie subjective rights and relevant legal obligations). For example, the set of subjective starting rights of family members forms a generalized family law; the set of subjective starting rights related to work, form a generalized labor law; the set of starting rights of different subjects to economic activity forms a generalized economic law, etc.