Objective：This study aims to investigate the risk factors of pulmonary hypertension in neonates. Methods：From January 2017 to December 2019，41 neonates with pulmonary hypertension admitted to the neonatal ward of the First Affiliated Hospital of Nanjing Medical University were collected and divided into preterm neonate group and full-term neonate group according to their gestational ages. The relationship between pulmonary hypertension and high risk factors such as primary disease and maternal high risk factors during pregnancy were analyzed retrospectively. Results：During the indicated three years，1 992 premature infants and 3 394 full-term infants were collected. Among them，23 premature（1.15%） and 18 full-term infants（0.53%） with pulmonary hypertension were included. There were significant differences in birth weight and gestational age between the two groups（P < 0.05）. No statistical differences in maternal age，gender，mode of delivery，twin or multiple births，and Apgar scores between the two groups（P > 0.05）. The incidences of premature rupture of membranes，placental abruption，chorioamnionitis and eclampsia in preterm group were higher than those in full-term group（P < 0.05）. The differences were statistically significant in the incidences of gestational diabetes mellitus between the two groups（5 cases in full-term group vs. 1 case in preterm group，χ2=4.437，P=0.035）. Compared with the full-term group，the major primary disease of preterm group was respiratory distress syndrome（χ2=19.158，P＜0.001），pulmonary hemorrhage（χ2=4.433，P=0.035）and intracranial hemorrhage（χ2=8.715，P=0.003），respectively. The primary disease in full-term group was mainly congenital heart disease（ventricular septal defect）（χ2=10.786，P=0.001）. There was a high occurence rate of neonatal pneumonia in both groups，but no statistical difference was shown（χ2=0.327，P > 0.05）. There were no statistical differences in metabolic acidosis，neonatal hypoglycemia，pneumothorax and septicemia between the two groups（P > 0.05）. In preterm group，21 cases were cured and 2 cases died. 15 cases were cured and 3 cases died in full-term group. No statistical difference was found in treatment effect between the two groups（P > 0.05）. Conclusion：The high-risk primary diseases of pulmonary hypertension in premature infants included respiratory distress syndrome，severe pneumonia，pulmonary hemorrhage，premature rupture of membranes and placental abruption. For full-term infants with congenital heart disease such as ventricular septal defect，timely diagnosis and treatment against pulmonary hypertension should be paid more attentions.