Objective To evaluate the importance of modulation transfer function (MTF) and visual electrophysiology in the early onset of diabetic retinopathy (DR).Methods It was a cross-sectional study.A total of 240 eyes were studied,including 48 no lesions diabetic retinopathy (NLDR) patients (80 eyes),52 non-proliferative DR patients (NPDR) (80 eyes) and 40 normal controls (80 eyes).The MTF,electroretinogram (ERG) and pattern visual evoked potential (PVEP) were measured.Data were analyzed with an independent samples t test.Results For high frequencies,MTF of NLDR and NPDR patients showed a significant reduction (P＜0.05),the ERG Op2 of the NLDR and NPDR patients showed a decline in amplitude and an extended incubation period (P＜0.05),the PVEP P100 for the non-proliferative DR patients showed a decrease in amplitude and an extended incubation period (P＜0.05),but there was no significant difference in the DR patients.The positive rate of combined testing of MTF and ERG Op2 for NLDK patients was 76％ and it was 90％ for NPDR patients.Conclusion The combined applications of MTF and ERG Op2 has a high sensitivity,which is important for the early detection of retinal damage.