목적: To maintain low Na+ concentration in the endolymph, Na+ transport from endolymphatic space to perilymphatic space is essential, which plays an important role in the normal function of hearing and balance. So far, it has not been reported about the Na+ transport of ampulla which is a part of vestibular system and contributes to sensing angular acceleration. We tried to investigate Na+ transport in the ampullary roof epithelium using electrophysiologic and pharmacologic method. 방법:Ampullary portion of vestibule was harvested from C57/BL6 mouse by microdissection. Scanning vibrating electrode system was applied to measure specific transepithelial current from ampullary roof epithelium. 결과:Ampullary portion of vestibule was harvested from C57/BL6 mouse by microdissection. Scanning vibrating electrode system was applied to measure specific transepithelial current from ampullary roof epithelium. 결론:Na+ absorption from endolymphatic space of ampulla was accomplished by ENaC on the apical surface of ampullary roof epithelium coupled with NKCC and Na+, K+ - ATPase. This contributes to the endolympahtic Na+ homeostasis of ampullary space of vestibular system.