Abstract: 　Objective　To explore the incidence, risk factors and tidal breathing pulmonary function of bronchopulmonary dysplasia (BPD) in premature infants with different gestational age. Method　The incidence of BPD in preterm infants in recent 4 years was analyzed retrospectively. Tidal breathing pulmonary function was compared among mild, moderate and severe BPD. Results　In 8538 premature infants, BPD occurred in 355 infants (4.16%). The incidence rates of BPD in preterm infants with different gestational age were 33.91% (<28 weeks), 8.85% (28~32 weeks), 1.63% (32~34 weeks) and 0.31% (34~37 weeks) respectively. There were 243 cases of mild BPD, 51 cases of moderate BPD and 61 cases of severe BPD. There were statistically significant differences in the gestational age, birth weight, hospitalization time, oxygen inhalation time and mechanical ventilation time among children with different severity of BPD (all P<0.05). The peak time ratio (27.73±9.26、21.43±5.73、16.15±4.90), and peak volume ratio (27.13±5.09、22.30±2.65、18.54±3.76) in the analysis of tidal breathing and lung function were also significantly different among children with different severity of BPD (all P<0.01). Conclusion　The incidence of BPD is related to the gestational age. Children with BPD had different degrees of damage in tidal breathing pulmonary function, and the more severe BPD has the more obvious limitation of tidal breathing pulmonary function.