AIM: To record multifocal electroretinogram from different dosage of N2O4 injected mice. In order to provide a foundation for further study. METHODS: Normal winstar mice which were injected by different dosage of N2O4 were studied for recording multifocal electroretinogram in the same time in the evening after N2O4 injection. RESULTS: The latency and amplitude density of "b" wave of each ring of multifocal electroretinogram was studied. The latency of "b" wave of each ring of multifocal electroretinogram of each group varies to each other. But the difference of the amplitude of "b" wave of multifocal electroretinogram of each ring between each group had no significance. CONCLUSION: Recording multifocal electroretinogram of N2O4 injected mice will give more support for further study in related science and clinic research.