The article attempts to formulate the principles of legitimacy of law since this issue is relevant but still remains debatable. Sources of law are being accepted in which power law prevails over power of law. In Soviet society, there was no right at all, because instead of legal laws, the law of the Communist Party dominated. Among the basic principles of legal legitimacy author identifies the principles of constitutional fundamentalization, popular representation, election of the parliament, judicial control over legislative activity. In addition, the legitimacy of law is ensured by legislative regulation of the legislative process, public participation in the preparation and discussion of draft laws, and professional and creative use of the rules of legislative technology.