Objective To explore the predictive value of lung ultrasound score on the severity of neonatal respiratory distress syndrome(NRDS).Methods The clinical data of 65 children with NRDS in our NICU from July 2021 to July 2022 were retrospectively analyzed,and 65 children were included in the NRDS group,while 40 children with other common pulmonary diseases(neonatal wet lung and infectious pneumonia)were selected as the other pulmonary disease group during the same period,and all children were examined by pulmonary ultrasound and X-ray to observe the children in both groups.The lung conditions of the two groups of children were observed:abnormal pleural line,disappearance of A line,isolated B line,fused B line,diffuse B line,lung consolidation,with or without bronchial inflation sign,and other lung ultrasound manifestations.The lung ultrasound scores of the two groups of children were compared,and the X-ray grading distribution of children in the NRDS group was analyzed,correlation between lung ultrasound scoring and X-ray grading was used by Pearson correlation analysis.The clinical value of lung ultrasound score in the differential diagnosis of NRDS and the severity of the disease was analyzed by receiver operator characteristic(ROC)curve.Results The proportion of solid lung,abnormal pleural line,disappearance of A-line,white lung detection,fused B-line,and bronchial inflation sign was significantly higher in the NRDS group than in the other lung disease groups,and the proportion of isolated B-line and double lung point detection was significantly lower than in the other lung disease groups,with statistically significant differences(P<0.05).The lung ultrasound scores of both lungs,left lung,right lung,bilateral lung,and base of both lungs were significantly higher in the NRDS group than in the other lung disease groups(P<0.05).With the increase of X-ray grading,the lung ultrasound score gradually increased,and there was a statistically significant difference between groups at each grade(P<0.05).Pearson correlation analysis showed that there was a significant positive correlation between lung ultrasound score and X-ray grade(r=0.704,P<0.05).The area under curve(AUC)of lung ultrasound score in differentiating NRDS from common lung diseases was 0.907,with sensitivity and specificity of 89.0%and 92.5%,respectively;the AUC of mild and moderate,moderate and severe NRDS in the differential diagnosis by lung ultrasound score was 0.914 and 0.933,respectively,which had high clinical value.Conclusion The lung ultrasound score has certain value in identifying NRDS.The lung ultrasound score can quantitatively assess the changes in the condition of NRDS,and the lung ultrasound and X-ray grading have good consistency,it has the advantages of radiation free,fast,and intuitive,and can be used as an effective method for early diagnosis of NRDS and evaluation of the severity of the disease.