This review shows the effects of oxytocin involved in bond formation and the manner of reciprocal communication leading to mother-infant bonding in rodents. Various social stimuli, such as tactile stimuli and ultrasonic vocalizations (USVs) from the pups to the mother, and feeding and tactile stimulation from the mother to the pups, reinforce the mother-infant bond formation in rats and mice. This suggests that the mother and infant are able to develop a cross-modal sensory recognition of each other. Although the mechanisms underlying bond formation in the brains of infants have not yet been clarified, oxytocin in the neural system plays a pivotal role in each sides of the mother-infant bonding process. The deprivation of social stimuli from the mother strongly influences the offspring’s sociality, including maternal behavior towards their own offspring, which implies the “non-genomic transmission of maternal environment.” The comparative understanding of cognitive functions between mother and infants, and the biological mechanisms involved in mother-infant bonding may help us understand psychiatric disorders associated with mother-infant relationships.