Objective:To analyze the risk factors of first endotracheal extubation failure and the related poor outcomes of extubation failure in intubated very low birth weight (VLBW) and extremely low birth weight (ELBW) infants.Methods:The VLBW/ELBW infants intubated in the first 24 hours, and admitted from June 2016 to December 2017 in Neonatal Intensive Care Unit of the Children′s Hospital of Fudan University were recruited in the study, and they were divided into 2 groups of the extubation-failure group and the extubation-success group based on whether being reintubated in 72 hours after the extubation.The clinical data of all children were collected, and risk factors and the short-term outcomes were compared between the 2 groups.Results:One hundred and twenty-six VLBW/ELBW infants including 25 extubation-failure infants and 101 extubation-success infants were recruited, the extubation fai-lure rate was 19.8%.Extubation-failure infants had lower gestational age and lower birth weight compared with those of extubation-success group [gestational age: (27.9±2.1) weeks vs.(28.9±1.6)weeks; birth weight: 990(847-1 200) g vs.1 170(1 060-1 350) g], and the differences were statistically significant (all P<0.05). The multiple Logistic analysis demonstrated that lower gestational age was the independent risk factor of extubation failure( OR=0.92, 95% CI: 0.86-0.99, P<0.05). The outcome analysis showed that the combined outcomes of moderate-to-severe bronchopulmonary dysplasia(BPD) and death in the extubation-failure group were significantly higher than those in the extubation-success group ( OR=3.33, 95% CI: 1.28-8.63, P<0.05)after being adjusted by gestational age.The secondary outcomes of brain magnetic resonance imaging(MRI) abnormality rate in the extubation-failure group was significantly higher compared with the extubation-success group ( OR=3.93, 95% CI: 1.22-12.60, P<0.05), and the mechanical ventilation duration was significantly longer as well in the extubation-failure group compared with that in the extubation-success group[10.1 d (6.9 d, 20.9 d) vs.3.6 d(1.1 d, 8.6 d)], and the difference was statistically significant( P<0.05). The rest secondary outcomes were not significantly different between the 2 groups(all P>0.05). Conclusions:A high rate of extubation failure in VLBW/ELBW infants was a common issue, and the lower gestational age is the independent risk factor for extubation failure.Extubation failure potentially increases the risk of moderate-to-severe BPD or death in VLBW/ELBW infants.