Oxytocin influences a wide range of human behaviors. Previous studies have suggested that these effects of oxytocin on human behavior are based on association with approach/withdrawal behavior. To test this hypothesis, we investigated whether the oxytocin receptor gene (OXTR) rs53576 polymorphism affects behavioral inhibition/activation system (BIS/BAS) sensitivity in healthy university students (n = 290). Our results show a significant allele-load-dependent increase by the G allele of OXTR rs53576 in BAS score, supporting previous findings that oxytocin increases approach-related behavior. Meanwhile, BIS score did not show a significant allele-load-dependent effect of OXTR rs53576, and association between oxytocin and withdrawal-related behavior is not suggested from the present study. Since the effect of OXTR rs53576 polymorphism on BAS sensitivity in the present study was relatively small, replication in a larger sample is needed to confirm this finding.