Objective To study the features of ultrasonography ( LUS) of lung diseases in neonatal intensive care unit ( NICU) .Methods Total 1413 neonates admitted in NICU of Beijing Chaoyang District Maternal and Child Health Hospital , Bayi Children′s Hospital Affiliated to the Chinese PLA General Hospital, Shenzhen Bao′an Maternal and Child Health Hospital from December 2014 to February 2015 were included in this study .All the newborns underwent LUS examination , the ultrasonographic features of neonatal lung diseases were analyzed .Results There were 1059 cases (74.9%) with lung diseases among 1413 neonates .Among 354 neonates without lung diseases , the B-lines were observed in 351 cases (99.2%) within 3 day after birth, in 113 cases (31.9%) in 3 day to 1 week after birth, and in 23 cases in 1 to 2 weeks after birth .Among 491 neonates with lung diseases undergoing LUS examination within 48 h after admission, the A-lines disappeared in all patients; the other features included pleural lines abnormalities (n=440, 89.6%), interstitial syndrome (n=353, 71.9%), lung consolidation(n=423, 86.25%), pulmonary edema ( n =135, 27.5%) and lung pulse ( n =96, 19.6%).The reduction or elimination of above abnormal signs represented the alleviation of lung diseases .Fifty four neonates , in whom the lung diseases were not detected by X-ray, were diagnosed as transient tachypnea of newborn (TTN), respiratory distress syndrome (RDS)and pneumonia by LUS.Fifty five patients, who were misdiagnosed with RDS by X-ray, were confirmed as TTN by LUS .Seventy one neonatal patients with long-term oxygen dependence , in whom no abnormal signs were detected by X-ray, underwent LUS examination and lung atelectasis, pulmonary consolidation and/or interstitial syndrome were diagnosed in 46 cases.Conclusion The LUS is practical and effective in diagnosis of neonatal pulmonary diseases , it is a non-irradiative diagnostic procedure and can be applied on bed side;therefore, it should be routinely used in NICU .