Objective To analyze the serum metabolomic changes of preterm infants with bronchopulmonary dysplasia (BPD) at postmenstrual age (PMA) 36 weeks, screen potential biomarkers and associated metabolic pathways, and assess their relationship with short-term respiratory outcomes. Methods A retrospective case-control study was conducted. Infants with gestational age 28-32 weeks admitted to the Children's Hospital Affiliated to Zhengzhou University from January to December 2024 were included. Twenty infants with BPD and 20 gestational age-, birth weight-, and sex-matched non-BPD preterm infants were included. Serum collected at PMA 36 weeks was subjected to untargeted metabolomics analysis, and associations with short-term respiratory outcomes were analyzed. Results Thirteen potential biomarkers distinguishing BPD were identified (area under the curve >0.75, P<0.05). Eight biomarkers—including terephthalic acid, phosphatidylinositol, fumarate, and lysophosphatidic acid—were significantly upregulated (FC≥1.5), while five biomarkers, such as 7α-hydroxy-3-oxo-4-cholestenoate ester and phosphatidylcholine, were significantly downregulated (FC≤1/1.5). Pathway analysis indicated five pathways associated with BPD, including glycerophospholipid metabolism and phenylalanine metabolism. Dysregulation of glycerophospholipid and bile acid metabolism may affect adverse short-term respiratory outcomes in infants with BPD. Conclusions The 13 significantly different metabolites may serve as biomarkers for the diagnosis of BPD. Glycerophospholipid metabolism is associated with the occurrence of BPD and with adverse short-term respiratory outcomes.