Microdissection have been used in attempt to observe the inner fluid spaces that the organ of corti has. By using this method, structures exposed into this fluid spaces could be examined and recorded under scanning electron microscope. A group of guinea pigs were treated with intraperitoneal inlection of streptomycin 250mg/kg/day and another group were given kanamycin 400mg/kg/day. Both groups were treated for 10 days, and than decapitated following the day of the last inlection. Microdissection using a small double-sided adhesive tape was used. This method is simple, easy to perform and provides a good possibility to observe the lateral wall of the space of Nuel. Our previous findings in the studies of normal nerve endings of outer hair cells were reviewed as the control. Although there were clearly evidence of ultrastructural changes in the cilia and their hair cells, nerve endings on the lower pole of outer hair cells seemed to be resistance to the effect of streptomycin or kanamycin. Further studies are in progress at our department to solve more this problem.