The article deals with various problems concerning vows undertaking by magistrates, first of all concerning temple’s building. This was a required phase of public temple’s foundation in the Roman Republic. Taking a vow had always been an individual act, even if it was made according to the Senate decision. Vows undertaken by magistrates on own initiative are ambiguous. On the one hand such vow was a personal magistrate’s obligation to the gods, on the other society understood its own responsibility for the fulfillment of vows undertaken by the magistrates they elected, although it was partially. Such a «responsibility feeling» no doubt sharpened in the case of military defeats, epidemics etc. Thus a person and a society existed in a harmony: a citizen executing a vow that he undertook for the profit of a society could rely on society’s help and support, however a society was independent of hasty words and acts of its member. Notwithstanding there are no evidence of formal control over the magistrate’s vows fulfillment (including ones concerning temple’s building). Society support wasn’t rendered automatically, but every case required a special decision of the senate. This is a typical situation in the sacral sphere and it could be observed in various aspects of the religious life in Roman Republic.