In the modern period of the demographic crisis, the study of reproductive behavior leading to large families becomes relevant. The authors made an attempt to describe the features of reproductive behavior based on the analysis of narrative interviews with large families parents. In the course of the analysis, the authors came to the conclusion that the determining factors of the transition to large family (having children in general) are, firstly, the dynamics of the reproductive attitudes of mothers under the influence of the characteristics of life situations, and secondly, the peculiarities of the contraceptive behavior of mothers (partners). It was revealed that modern large families are not the result of “high” attitudes towards motherhood at the beginning of the reproductive period. In many ways, large families arise as a response to certain life events (mating, stressful, reproductive, etc.). Based on the criteria of “initial reproductive attitudes” and “temporally-conscious attitude to birth planning”, four models of large families (traditional, conscious, spontaneous, transforming) were constructed.