Abstract: Objective To explore the incidence and risk factors of brain injury in preterm infants through a prospective cohort study.Methods All preterm infants were recruited from January 1 st 2016 to December 30 th 2016, excluding severe congenital and malformation disorders. The basic clinical data of the infants were recorded. Cranial MRI examination was taken at corrected gestational age of 36-42 weeks or before discharge from hospital. The perinatal risk factors of brain injury in preterm infants were analyzed.Results A total of 232 preterm infants fulfilled the screening criteria and 232 finished a follow up. Among them, 148 were male and 84 were female. The mean gestational age was (31. 02 ± 2. 96) weeks. Mean birth weight was (1710. 09 ± 545. 23) g. There were 121 cases of very low birth weight infants and 92 cases of over low birth weight infants. And 32 infants (13. 79%) had brain injury.The results of univariate analysis showed that 1 min Apgar scores, 5 min Apgar scores, patent ductus arteriosus requiring treatment (including pharmacologic and/or surgical treatment), neonatal necrotizing enterocolitis and sepsis, and parenteral nutrition > 14 days were associated with brain injury (P < 0. 05). Logistic regression analysis showed that 1 min Apgar scores (OR=0. 138), neonatal ecrotizing enterocolitis (OR=0. 319) and sepsis (OR=0. 258) were independent risk factors for brain injury.Conclusions The main risk factors of brain injury in preterm infants are hypoxia and infection. It is necessary to strengthen antenatal care, to prevent preterm birth, actively prevention of infection and hypoxia in preterm infants.