The research is dedicated to the analysis of law enforcement civil aspects in legal regulation of public relations, determination of its character and value as security instrument of their effectiveness. It is set that law realization is considered in such forms as law fulfillment, law application, law enforcement, law fulfillment and law termination accompanying the motion of civil-law relations. Law enforcement legal nature is stipulated by the objective necessity to influence on the behavior of participants of such civil-law relations to ensure their compliance with the legal model. It is proved that the reason for law enforcement in the course of civil-law relations realization is such character of their development, reality and affiliation of which in view of their social value is provided individually-legal instructions given by public authority. Realization of subjective civil rights and legal obligations in private relation is provided by the acceptance of individual legal act issued by governmental authority. Law enforcement mechanism in a private law was considered whereby the combination of legal measures through which public activity of governmental authority is adjusted should be understood, which involves adjustment of civil-law relations in the course of their legal regulation, provision of stable public society development. Authority’s activity in law enforcement mechanism is provided by the system of legal measures (mechanism elements), the total amount of which shall be naturally implemented in law realization mechanism the component of which is law enforcement mechanism in synchronically directed at provision of its effectiveness. To such elements of law enforcement mechanism each of which is specified within the appropriate law realization may be included: legal provision, legal relations and judicial fact.