In animals, it is known that the basal fibers of the cochlear nerves are located peripheral to the apical fibers. And also, there are various reports on the size of fibers from different regions of the cochlea according to the conduction frequency. This is a report of the tonotopic organization of the human cochlear nerve. According to this study, the basal turn fibers of the human cochlear nerve were found to be located peripheral to the apical fibers, which were close to the vestibular nerve on the cross-section of the nerve trunk. Based on this study, the following results were obtained. Fibers from the basal turn were thicker than those from the apical turn by the ratio of 1.36 to 1.46. This was different from the findings in cats, in which the apical turn fibers were thicker than the basal turn fibers. The size of the fibers at specific locations in the cross-section of the human cochlear nerve trunk was variable. We hypothesize that the cochlear nerve is consists rosettes of one thick fiber surrounded by several thin fibers. This paper provides morphologic data that will promote the understanding of the structure and function of the cochlear nerve.