Abstract: Objective: To examine the effects of cochlear ischemia at different levels on the cochlear microcirculation and the cochlear functions in guinea pigs.Methods: Anterior inferior cerebellar artery and the posterior inferior cerebellar artery were compressed with various pressures. The microcirculations in the cochlear lateral wall were observed and the amplitudes of brain stem response (ABR) were measured during and after the arterial occlusion. Results: ABR amplitudes were kept constantly if cochlear blood flow changes were mirror or moderate. However, if the blood flow decreased markedly, the ABR amplitudes decreased or even totally abolished. The decreased volume of the blood flow to the cochlea affected the blood flow more dramatically in the vessels of the stria vescularis than that in the spiral ligament. When the blood flow in these vessels stopped, the amplitude changes of ABR were largely associated with blood flow in the vessels of the spiral ligament.Conclusion: The potential capacity of blood flow to the cochlea exceeds the actual requirement of the cochlea to maintain its normal function. When the blood flow to the cochlea severely decreases, keeping the blood flow in thd vessels of the spiral ligament is crucially important in maintaining the cochlear functions.