Abstract： AIM:To investigate the value of pattern visual evoked potential (PVEP) and flash electroretinogram (FERG) in early diagnosis and prevention of diabetic retinopathy (DR), analyzing the correlation of early stage DR with PVEP and FERG. <br> METHODS: Sixty patients, 30 males and 30 females, participated in observation group. Their average age was 19. 42 ± 7. 78years. The duration of DM was < 5a. Best corrected visual acuity was 5. 0. Fasting blood glucose was 7. 8± 3. 6mmol/ L. There were 60 subjects, 30 males and 30 females, in control group. Their average age was 17. 2 ± 6. 52years. Best corrected visual acuity was 5. 0. Every participator was tested with PVEP and FERG according to ISCVE standard. The amplitude of PVEP and P100 latency were recorded. And the b-wave latency, b-wave amplitude, a - wave latency, a - wave amplitude were showed down. <br> RESULTS: In observation group, P100 amplitude&nbsp;decreased and P100 latency increased, compared to those of control group ( P< 0. 01); b - wave latency, b -wave amplitude, a - wave latency, a - wave amplitude were different from those in control group(P<0. 01); the fasting blood glucose kept stable; P100 amplitude, b -wave amplitude and a-wave amplitude were not related to the DM duration; P100 latency, a-wave latency and b-wave latency were related to the DM duration. <br> CONCLUSION: PVEP are sensitive to optic neuron damage; FERG is desirable to detect the lesion of Müller cells and bipolar cells. P100 amplitude by PVEP, b-wave amplitude by FERG may be the most sensitive parameter for DR at early stage.