ENArticle aims to clear out and aggregate the possible ways of evaluating the significance of legal, economic and social instruments established to increase fertility. First of all, this requires to describe models used in research literature describing links between family policy instruments and the result, and then to make a list of significance criteria under the selected models for the evaluation of possible ways to examine the significance of family policy instruments. The article divides family policy instruments for the increase of fertility into legal, economic and social instruments. Taking into account the fact that in teleological respect, any instrument may be both social (addressed to particular groups in society) and legal (i.e. laid down in laws), this division needs a more detailed explanation. The classification criteria for family policy instruments were accurateness and the aggregation capacity. Thus, legal instruments are held instruments of general nature, describing legal status and basic human rights (instruments ensuring equality of persons, obligation of third persons in relation to family members, etc.) which may not be evaluated in economical terms. Economic instruments are instruments expressed in monetary form, i.e. various allowances, benefits, compensations and tax exemptions. Finally, social instruments are instruments in other forms, not directly expressed in monetary form; however, the value thereof is subject to economic evaluation, including forms of work and family conciliation instruments, childcare possibilities, etc.The article consists of three parts. The first part describes theoretical assumptions for the evaluation of significance of legal, economic and social instruments for the increase of fertility, i.e. analyses the conception of legal, economic and social instruments, research models of evaluation of their significance and makes a set of criteria for the evaluation of significance of the instruments under consideration. The second part presents methodology and restrictions for evaluation of significance of legal, economic and social instruments for the increase of fertility. The third part includes a pilot study seeking to evaluate the possibilities to make inferences on the significance of legal, economic and social instruments using the statistical and other necessary data already accumulated in state and research databases in Lithuania. [From the publication]