Objective To observe the characteristics of the full-field flash electroretinogram (F-ERG) in rats with oxygen induced retinopathy (OIR). Methods Twenty-four neonatal Sprague Dawley rats were divided into OIR group and control group. In OIR group, 12 rats were exposed to (75±2)% oxygen for 7 days and then to room air for 7 days; in control group, 12 rats were raised in room air for 14 days. At postnatal day 21, F-ERG tests were performed to examine the rod response , the maximum mixing reaction and the cone reaction. Results Compared with the control group, the b-wave amplitudes decreased (t=3.650) and the implicit times increased (t=2.410) in rod response in OIR group, the differences were statistically significant (P＜0.05); the a- and b-wave amplitudes decreased (t=3.333, 2.562) and the implicit times increased (t=2.725, 2.482) in the maximum mixing reaction in OIR group, the differences were statistically significant (P＜0.05). There was no difference between OIR and control group on a- and b-wave amplitudes (t=0.650, 0.204) and implicit times (t=0.422, 0.076) in cone response (P＞0.05). 0.001 cd.s/m2 light intensity stimulation on rats F-ERG wave almost no response. 0.010 cd.s/m2 light intensity stimulation on rats can be recorded to the rod response waveform, with the increase of light intensity, the amplitude of b-wave increases, the a-wave extraction. Conclusions F-ERG of OIR rat showed that the amplitude and sensitivity of the rod response and maximal rod-cone response was decreased. The intensity of light had effect on the OIR rod cells, and the amplitude of b- wave increased with the increase of light intensity, the a-wave extraction.