Objective To investigate the value of Notch 3 in the blood of preterm infants in the early diagnosis of bronchopulmonary dysplasia (BPD).MethodsA total of 78 patients with gestational age of 27 to 32 weeks received in Maternal and Child Health Hospital of Foshan City from January 2016 to February 2017 were recorded.There were 23 patients with BPD and 55%of non-BPD children.The BPD group was set as the observation group,and the children who had not been diagnosed with BPD were matched with the gestational age of BPD group in the neonatal department.The expression of Notch 3 in the two groups was measured.Results The values of Notch 3 in the observation group were significantly higher than those in the control group,and the difference between the observation group and the control group was statistically significant(P＜0.05).Conclusion Notch 3 is highly expressed in the pathogenesis of BPD,and Notch 3 has a high early diagnostic value for BPD.