Abstract: The endolymphatic sac (ES) is a part of the homeostasisregulating system of the membranous labyrinth of the inner ear. Factors that influence blood flow in the sac may affect its function. This blood flow may be influenced by autonomic innervation; however，no such innervation has been demonstrated. The purpose of this study is to confirm the existence of the nerve fibres on the endolymphatic sac. Methods: Fifteen healthy Swards white rats were divided into three groups randomly. The temporal bones were taken out and were processed and sectioned by paraffinembedded technique. The sections of ES were stained by the antibody that was not labeled by biotin including the antibody for neurone specific enolase (NSE), antibody for glial fibrillary acidic protein (GFAP) and antibody for neurofilament (NF). The slides were observed by light microscope. Results： On light microscope, the brown positive staining was observed in the epithelia of ES. However，there was not any positive staining on the negative control slides. Conclusion: Nerve fibers exactly exist in the epithelia of ES.

Key words: Endolymphatic sac, Nerve fibers, Meniere's disease, Immunohistochemistry