The article combines the presentation of traditional law perspectives on the nature, essence and meaning of the sources of law, and current views and concepts on the subject, with the realities. In his speech, the proposed approaches to the problems of the theory of sources of law. including; etymological (generally accepted understanding of the content and the concept of the category «source of law»); the study of law as a source of natural phenomena (geographic, climatic, biological, and other factors affecting the process the law-making process); social, political, ideological and cultural factors affecting the process of law-making, the study of the social component of the sources of law. Separate vector research is devoted to the sources of law in the broad sense (material, ideological and formal-legal significance) and narrow (a formal legal significance). Certainly the attention paid to the study of sources of law principles (objectivity, historicism, the unity of historical and logical, thorough, systematic method). Separate treatment — an issue devoted to the relationship categories «form of law» and «a source of law». In addition, the proposed brief review of the concept and the system of sources of European Union law.