Paternal care is necessary for the healthy development of social behavior in monogamous rodents and social recognition underpins social behavior in these animals.The effects of paternal care on the development of social recognition and underlying neuroendocrine mechanisms,especially the involvement of oxytocin and estrogen pathways,remain poorly understood.We investigated the effects of paternal deprivation on social recognition in mandarin voles (Microtus mandarinus),a socially monogamous rodent.Paternal deprivation was found to inhibit the development of social recognition in females and males according to a habituation–dishabituation paradigm.Paternal deprivation resulted in increased inactivity and reduced investigation during new encounters with other animals.Paternal deprivation reduced oxytocin receptor (OTR) mRNA and estrogen α receptor (ERα) mRNA expression in the medial amygdala and nucleus accumbens of female and male offspring.Paternal deprivation reduced serum oxytocin in females,but had no effect on males.Our results provide substantial evidence that paternal deprivation inhibits the formation of social recognition in female and male mandarin voles and alters social behavior later in life.This is possibly the result of altered expression of oxytocin receptor and estrogen α receptor and serum oxytocin levels caused by paternal deprivation.