Abstract： Objective To investigate the incidence and the risk factors of preterm infants with brain damage in neonatal intensive care unit (NICU). Methods Premature infants ≤34 weeks of gestation or ≤ 2000 g of birth weight, admitted to NICU of the Children's Hospital of Fudan University from February 2006 to January 2007, were included in this study. Transcranial ultrasound was performed serially. Clinical data of the patients were analyzed to determine the incidence and the risk factors of brain damage. Results Totally 328 preterm infants achieved serial transcranial ultrasound scan. IVH occured in 141 cases (43.0%), among which, 101 infants had mild IVH, and 40 had severe IVH. Thirty two (9.8%) preterm infants had white matter damage (WMD), 44 (13.4%) had persistent ventricular enlargement and 35 (10.7%) had intracranial cystic lesions at the first transcranial ultrasound scan. The average birth weight and gestational age for preterm infants with IVH or WMD were significantly lower than those without (P<0.05). Birth weight, neonatal infection, small for gestational age, mechanical ventilation were independent risk factors of IVH, and birth weight was the only independent risk factor of WMD. Conclusions The incidence of brain damage in preterm infants remains relatively high in NICU. Birth weight, neonatal infection, small for gestational age, mechanical ventilation are independent risk factors of IVH. Birth weight is the independent risk factor of WMD.