ObjectiveTo evaluate the characteristics of electroretinagram (EGR) in children with history of pre-threshold or threshold retinopathy of prematurity (ROP). MethodsA total of 24 children (48 eyes) with history of pre-threshold ROP or threshold ROP received F-ERG examination.Ten age and body weight-matched children with a history of premature birth (20 eyes) but without ROP were recruited as control group. The rod response, maximal rod-cone response and cone response of F-ERG were recorded respectively following the International Standard Protocal of ISCEV (2000 version).The latency and amplitude of a-wave and b-wave of various responses were analyzed. The trial was approved by the Ethic Committee of Hunan Children's Hospital and informed consent was obtained from the parents of patients prior to any medical procedure. ResultsThere was significant difference between ROP and control group in rod response,the latency was longer (t=5.643,P<0.05) and the amplitude was lower in ROP group(t=7.068,P<0.05).In maximal rod-cone response both in a and b wave, the latency wave was longer(t=3.099, 2.886;P<0.05) and the amplitude was lower(t=5.614, 2.850;P<0.05) in ROP group. But there is no difference between ROP and control group in cone response latency(t=0.819, 0.948)and amplitude(t=0.904, 0.850). ConclusionERG in ROP children with history of pre-threshold or threshold ROP is abnormal, which mainly in rod response,but the cone response remains normal.