Objective To retrospectively analyze the application of lung ultrasound in neonatal de-partment of our hospital in the past three years,and summed up the clinical diagnosis and treatment changes brought by it. Methods The clinical data of infants accepted the bedside lung ultrasound examination from May to December 2016(early carry out stage),from January to December 2017(adaptation stage),from Jan-uary to August 2018(normal conduct stage) in our NICU of Jingzhou Central Hospital were collected. The clinical data of 878 infants with different stages of application were compared and analyzed. Results In 878 children,1 225 of lung ultrasound were performed,64. 1% of patients had pulmonary disease,and 35. 9% had no lung disease. There were 67 cases of neonatal respiratory distress syndrome,278 cases of wet lung,259 ca-ses of pneumonia,64 cases of meconium aspiration syndrome,72 cases of acute respiratory distress syn-drome,63 cases of atelectasis and 14 cases of pleural effusion. A total of 1 122 times of lung X-ray examina-tion were performed in 878 children. The number of X-ray examinations per capita decreased from 2. 48 times in 2016 to 1. 40 times in 2017 and 0. 84 times in 2018. A total of 32 times of pulmonary CT examination were performed. The number of lung CT inspection decreased from 0. 060 times in 2016 to 0. 038 times in 2017 and 0. 029 times in 2018. Lung ultrasound was convenient for dynamic observation,and could be used to de-termine the improvement,aggravation or new pulmonary lesions. Conclusion Lung ultrasound is accurate in the diagnosis of lung disease in NICU,especially for children with long hospital stay,repeated illness and dif-ficult to withdraw. It is easy to carry out in clinic,at the bedside,which can reduce the times of chest X-ray and CT per capita examination. Lung ultrasound is an effective and feasible method for NICU to diagnose lung diseases and it is worth promoting.