Abstract: Determining ontological nature of family relationships has both – theoretical, as well as practical value. In order to study this issue, it is necessary to establish the notion of family relations and the nature of actual relationships protected by law. Moreover, it must be determined what the legal status of a child born out of wedlock is. Generally, the present paper demonstrates that family relationships should be regarded as both – regulated by family law and by actual family relationships. Unmarried relationships (relationship without marriage registration) of partners do not invoke legal outcomes between them. Their relationship is recognized solely for the purposes of the protection of a child. In this sense, the birth of a child is important, since the relationship between children and parents are regulated by family law. The fact leads to either the alimony obligation or to the right to heritage.