AIM:To observe the characteristics of the images of multifocal electroretinogram (mf-ERG)performed on the patients with severe proliferative diabetic retinopathy（PDR)and its clinical significance. METHODS:Forty PDR patients(44 eyes) and forty normal control subjects (40 eyes) were tested with mf-ERG. The data were processed with software SPSS 13.0. RESULTS:mf-ERG showed the response densities of ring 1-ring 5 areas in PDR were significantly decreased while the latencies of ring 4 of N1 wave and the latencies of ring 2,ring 3,ring 4 and ring 5 of P1 wave were significantly prolonged with normal control group. CONCLUSION:mf-ERG can provide more information to evaluate the retina function effectively in PDR.