Objective To investigate the effects of myopia on first-order kernels six ring responses of multifocal electroretinogram (mfERG). Method We continuously selected 80 subjects aged from 13 to 20 year-old and divided four groups into normal, mild myopia, moderate myopia and high myopia. Each group had 20 subjects that were examined with mfERG of 103 stimuli locations. The amplitude and latency of N1, P1, N2 waveforms of six-ring first-kernel responses in mfERG were analyzed. Result With increasing of myopia degree, the response density of N1, P1, N2 waveforms of six-ring first-kernel responses in mfERG was decreased gradually (all Plt;0.05). However, latency of N1, P1, N2 waveforms of six-ring first-kernel responses in mfERG didnrsquo;t change significantly (all Pgt;0.05). Conclusion Myopia can decrease the response density of first-order kernels six ring responses of mfERG, which is very important to determine the abnormality of mfERG in the clinic. (Chin J Ocul Fundus Dis, 2006, 22, 103-105)