Objective To analyze the epidemiological characteristics of children with bronchopulmonary dysplasia (BPD) for 6 years and clinical characteristics changes of BPD in different periods. Methods Clinical data of children with confirmed BPD after birth and during the mother's pregnancy from January 2015 to December 2020 were retrospectively collected. The children were grouped according to the gestational age and birth weight, and the trend of BPD incidence in each group was compared. According to the time of diagnosis, the children were divided into group 2015-2017 and group 2018-2020 and the clinical characteristics of the two groups were compared. Results From 2015 to 2020, a total of 1237 premature infants with gestational age <32 weeks were admitted to our hospital, including 155 infants with BPD (12.5%). There was significant difference in the incidence of BPD among different gestational age groups (P<0.001). The incidence of BPD among premature infants ≤26 weeks was the highest, and the incidence of BPD decreased with the increase of gestational age. From 2015 to 2020, the gestational age distribution of children with BPD showed statistically significant differences among different years (P=0.001). In 2015 and 2016, the proportion of patients with gestational age of 28 to 32 weeks was higher. The proportion of patients with gestational age of 26-29⁺⁶ weeks from 2017 to 2020 was higher. The incidence of BPD among different birth weight groups was significantly different (P<0.001). The incidence of BPD among premature infants ≤750g was the highest, and the incidence of BPD decreased with the increase of birth weight. From 2015 to 2020, there were statistically significant differences in the birth weight distribution of BPD children in different years (P<0.05). In 2015 and 2016, the proportion of patients with birth weight of 1001-1500g was higher. In 2017 and 2018, the proportion of patients with birth weight of 751-1500 g was higher. In 2019 and 2020, the proportion of patient with birth weight of 751-1250g was higher. Compared with group 2015-2017, BPD children in group 2018-2020 had lower gestational age, lower birth weight and NCIS score, lower proportion of physical body weight decline ≥10%, higher proportion of maternal smoking or exposure to polluted air, higher proportion of respiratory failure and anemia, longer time to start enteral nutrition and to reach complete enteral nutrition. The difference between the two groups was statistically significant (P<0.05). Conclusions BPD happens in early gestational age and cause low birth weight of children. For children with maternal exposure to smoking or air pollution, respiratory failure and anemia after birth, BPD should be considered in clinical work.