Oxytocin is involved in the regulation of the menstrual cycle. The paper describes the synthesis of hormone in the various organs of the female body and describes the construction of oxytocin receptor. Characterized factors affecting the biosynthesis and changes in oxytocin receptor density in the tissues of the reproductive system during the menstrual cycle. Describes in detail the participation of oxytocin in the regulation of luteolysis with regard to species differences in sheep, cows and pigs.