Abstract: The guinea pigs were immunized with the homogeneous antigen. Six weeks after immunization, sensorineural hearing loss occurred in 33 ears among 25 immunized animals, with an incidence of 66% (33/50). The pathological changes in the inner ear of immunized animals were observed by celloidin section, enzyme histochemistry, transmission electron microscopy, and immunohistochemistry. The results confirmed that the sensorineural hearing loss was induced by the immune reaction. The pathological characteristics and the pathogenesis of autoimmune sensorineural hearing loss were discussed.