Objective To explore the use and relative factors analysis of flash visual evoked potentials(FVEP) in neonatal intensive care unit and provide the scientific basis for the diagnosis of visual function. Methods Thirty premature infants with two or more kinds of serious complications from neonatal intensive care unit were selected as experimental group,and thirty full-term newborns from common neonatal wards were selected as control group.Any case with brain injury was excluded.All infants were evaluated by FVEP 1 to 2 weeks after entering the hospital.All cases with abnormal findings were followed up by 3 months and 6 months after birth. Results Gestational age was closely related to clinical latency.The shorter the gestational age was,the longer was the P100 latency,with significant difference(P＜0.01).The major risk factor of the dominant wave deficiency was related to hyperbilirubinemia,asphyxia,hypothyroidism.In 16 cases(26 eyes) of premature infants with abnormal findings of FVEP,there were 8 premature infants were recovered totally,with no change in 1 case and loss to follow up in 7 cases.In the group of term infants,the latency of P100 was recovered after 6 months in 4 cases (6 eyes) with abnormal FVEP. Conclusions FVEP is an objective methods for visual function state in premature infants with wonderful accuracy,sensitivity and better repeatability.FVEP is helpful to understand the damage of nervous system in preterm infants.Hperbilirubinemia,asphyxia and hypothyroidism are regarded as the highly risk factors of brain injury in preterm infants.