The ultrastructures of the vestibular sensory hairs were examined using rapid-freeze, freeze-substitution method. The stereocilia, which had actin filaments in it, were well preserved in this method. The glycocalyx covered the stereocilia, and was considered to play an important role in keeping position of stereocilia and bending them together. In this study, the glycocalyx appeared to be amorphous rather than fibrous. This method showed new ultrastructual findings differed from those of the conventional chemical fixation.