The oxytocin neural system plays a critical role in a variety of social behaviors and recognition. Mice mutant for oxytocin gene (Oxt-/-) fail to display social memory despite apparently normal olfactory learning ability. Oxytocin is also thought to be involved in underlying mechanisms that guide the development of social behaviors. In the present study, we examined whether neonatal oxytocin treatments recovered social deficits in Oxt-/- mice. Oxt-/- male pups, together with male littermates of heterozygote (Oxt+/-) and wild-type (Oxt+/+), received intraperitoneal injections of oxytocin or saline on postnatal day 0, 2, 4, and 6. After grown up to be adult, social memory and preference for social novelty were examined. We characterized social memory in male mice by habituation-dishabituation test using ovariectomized female mouse. Only Oxt-/- mice having been treated with saline showed no decline in time spent investigating the female mouse, indicating that Oxt-/- mice did not develop social memory as had been reported. However, Oxt-/- mice having been treated with oxytocin showed a characteristic decline in the time, with a full recovery following the introduction of a new female. The preference for social novelty was evaluated by comparing times spent investigating between familiar and unfamiliar ovariectomized female mice. Irrespective of the neonatal treatments, Oxt+/+ mice spend significantly more time with the unfamiliar female than with the familiar female, indicating the preference for social novelty, but Oxt-/- mice did not show the preference. Interestingly, Oxt+/- mice having been treated with saline did not show the preference, but Oxt+/- mice having been treated with oxytocin did. These suggested that neonatal oxytocin treatments recovered social memory in Oxt-/- mice and preference for social novelty in Oxt+/- mice. Neonatal oxytocin may have some organizational abilities for the development of social behaviors.