In the authors' opinion and in the context of contemporary science of constitutional law, the doctrine, the rule-maker (in a broader sense) and jurisprudence of the Constitutional Court of Russia give dynamism to the subject matter of constitutional law. If regarding the role of the latter in extending and deepening the constitutional law subject matter modern scholars' opinions are generally unanimous, since this happens on the basis of powers constitutionally enshrined by the "will of the State giving these relations a fundamental character" (Oleg E. Kutafin), the influence of the doctrine and regulations on the extension of constitutional law needs more thorough consideration. The author, using regulatory acts and doctrinal provisions as examples, demonstrates an imaginary and actual extension of constitutional law subject matter. Arguing her point of view, the author warns us against further imaginary extension of the subject matter of the leading branch of the Russian legal system and highlights promising areas with regard to further extension of the doctrinal basis and thereby expanding the constitutional law subject matter.