Oxytocin has been reported to modulate human behavior in many social interactions of which attachment between mother and child is the child's first social relationship. Quality of the attachment might affect the sensitivity of child's stress regulation system by modulating the development of the child's oxytocin system. This might affect social behavior in adulthood and could be one of the risk or resilience factors for mental disorders and coronary artery diseases. Oxytocin has been linked to conditions like autism and depression that significantly disturb social interaction capabilities and coping with daily life activities. Better treatment and preventative methods might be found to those diseases by investigating the effects of oxytocin to the formation of the mother-child attachment and child's development.