Repeated separations from pups produce anxiety and depression like behavior in mother.The strong attachment has also been established between father and pups in monogamous rodents.We hypothesized that brief and long time pups separation can also affect emotion,social behavior and neuroendocrine parameter differently in socially monogamous mandarin vole (Microtus mandarinus) fathers.The result indicated that brief pups separations (BPS,15min/d) significantly reduced percentage of time in central area,total distance and total transition in open field test,while long pups separations (LPS,3h/d) increased immobility time in forced swimming test.In addition,BPS increased sniffing and self-grooming,but reduced attacking and climbing.However,LPS increased staying,but suppressed attacking,sniffing,investigating and digging.Furthermore,LPS significantly up-regulated levels of central OT and AVP,and serum OT and corticosterone,while BPS only increased central OT and serum corticosterone.Taken together,present data indicated that BPS and LPS are critical stressors for the fathers which can induce psychological disorders such as anxiety and depression respectively in monogamous mandarin voles.They also affect social behavior of fathers differently.These changes in behaviors are associated with alteration in OT,AVP and corticosterone levels.