High leukocytes in newborns are not dangerous if they are physiologic and more dangerous if they are pathologic. Early neonatal leukocytes within 7 days of birth normal range is (5~25)*10⁹/L, 7~28 days of birth of late neonatal leukocytes normal is divided into (5~15)*10⁹/L, higher than infants and adults are obviously much higher, in this range are normal. Elevated white blood cell count is not always a sign of disease, there are some physiological factors, stimulation will lead to increased secretion of catecholamines in the body, the appearance of white blood cells temporarily elevated. There are usually no other accompanying symptoms, and the newborn’s diet, sleep, and mental state are all normal and not dangerous. Infections in the newborn’s body can also cause elevated white blood cells, such as neonatal pneumonia, usually accompanied by poor mental health, lethargy, fever and other symptoms, which is a more dangerous situation. If a newborn has high white blood cells, he or she should consult a doctor immediately to clarify the cause and treat the symptoms.