Objective To study the characteristics of hearing loss caused by local microcirculatory disorders in the cochlea apical part of guinea pigs. Methods The local microcirculatory disorders in the cochlea apical part of guinea pigs were caused by photochemical reaction. Morphological changes were observed by light microscope. The CAP - N1 amplitude, CAP - N1 latency, CAP - N1 threshold shift and CM amplitude which were evoked by short tone burst were recorded by Madsen 2250. Re- sults Histopathological changes showed that microthrombosis in the capillaries of stria vascularies and spiral ligment were located in the apical and third turn of cochlea. The CAP - N1 amplitude, CAP - N1 latency, CAP-N1 threshold shift and CM amplitude showed that the hearing loss was remarkable in the low - range frequencies. Conclusion When the local microcirculatory disor- ders in the cochlear apical part took place, the hearing loss was more marked in the low - range frequencies.