objective: To investigate the effect of mitochondrial function mediated by phospholipase D1(PLD1) on lung of mice with bronchopulmonary dysplasia (BPD). Methods: Eighteen WT mice and 18 PLD1-KO mice were divided into the following four groups: normoxic +WT group, normoxic +PLD1-KO group, hyperoxic +WT group and hyperoxic +PLD1-KO group, with 9 mice in each group. The newborn mice in hyperoxia group were exposed to hyperoxia (85%O2) for 14 days. In normoxic group, newborn mice were exposed to normoxic conditions (21%O2) for 14 days. On the 14th day, the levels of oxidative stress, apoptosis and fibrosis in mice lungs were evaluated by commercial kits [malondialdehyde (MDA) and superoxide dismutase (SOD)], protein blot (Bax, Bcl-2, cleaved caspase-3) and immunohistochemistry (α-SMA, AIF). MLE-12 cells were divided into normoxic +si-NC, hyperoxic +si-NC, normoxic +si-PLD1 and hyperoxic +si-PLD1. After transient transfection, the cells were exposed to normoxia or hyperoxia for 24 h. Mitochondrial reactive oxygen species (ROS) and function were measured by MitoSOX Red and hippocampus mitochondrial stress test. Results: Compared with the normoxic group, α-SMA, AIF positive staining, MDA, Cleaved Caspase-3 and BAX in lung tissue of hyperoxic group increased significantly (P < 0.05), while SOD activity and BCL-2 decreased significantly (P < 0.05). The positive staining of α-SMA, AIF, the abundance of Cleaved Caspase-3 and BAX in lung tissue of hyperoxia +PLD1-KO group were lower than those of hyperoxia +WT group (P < 0.05), while the SOD activity and BCL-2 abundance were higher than those of hyperoxia+WT group (P < 0.05). Compared with normoxic group, the expression of AIF in mitochondria of MLE-12 cells in hyperoxic group decreased significantly (P < 0.05), but it increased significantly in cytoplasm (P < 0.05), and compared with hyperoxic +si-NC group, the expression of AIF in mitochondria of MLE-12 cells in hyperoxic +si-PLD1 group increased significantly (P < 0.05). The abundance of mtROS in MLE-12 cells in hyperoxia group was higher than that in normoxia group (P < 0.05), and the abundance of mtROS in MLE-12 cells in hyperoxia +si-PLD1 group was lower than that in hyperoxia +si-NC group (P < 0.05). Compared with normoxic +si-NC group, the basic respiration, ATP production, maximum respiration and standby respiration of hyperoxic +si-NC group decreased significantly (P < 0.05). Compared with hyperoxia +si-NC group, hyperoxia +si-PLD1 group significantly increased the basic respiration, ATP production, maximum respiration and standby respiration (P < 0.05). Conclusion: The key role of PLD1 in hyperoxia-induced mouse BPD and MLE-12 cells, the deletion of PLD1 gene may protect lung injury induced by hyperoxia exposure by resisting mitochondrial apoptosis.