【Abstract】 Objective To study the expression and correlation of platelet activating factor (PAF), tumor necrosis factorα (TNF -α), pulmonary surfactant protein A (SP-A) in neonatal acute lung injury. Methods In this paper, 70 newborns with acute lung injury treated in our hospital from September 2018 to September 2019 were divided into acute lung injury group, including 28 in recovery period, 42 in acute period, 63 in survival period and 7 in death period. 50 newborns with pneumonia treated in our hospital at the same period were divided into pneumonia group and 50 newborns examined in our hospital were divided into control group. The levels of PAF and TNF-α were detected by enzymelinked immunosorbent assay (ELISA), SP-A was detected by immune spot assay, and the correlation was analyzed by Pearson. Results The levels of PAF and TNF-α in pneumonia group and acute lung injury group were higher than those in the control group, and the levels of SP-A were lower than those in the control group (P＜0.05). The expression level of PAF and TNF-α in acute lung injury group was higher than that in pneumonia group, and the level of SP-A was lower than that in pneumonia group (P＜0.05). The expression level of PAF and TNF-α in acute stage was higher than that in convalescent stage, and the level of SP-A was lower than that in convalescent stage (P＜0.05). The expression level of PAF and TNF-α in death group was higher than that in survival group, and the level of SP-A was lower than that in survival group (P＜0.05). There was a positive correlation between PAF and TNF-α (r=0.485, P=0.001); there was a negative correlation between TNF-α and SP-A (r=0.358, P=0.002); there was a negative correlation between PAF and SP-A (r=0.245, P=0.041). Conclusion The expression of PAF, TNF-α and SP-A is abnormal in neonatal acute lung injury. There is a certain correlation between them. It is of great significance for the newborn to participate in the occurrence of neonatal acute lung injury.