The horizontal, vertical and cyclorotational components of eye movements were analyzed in 8 cases of dissociated vertical deviation (DVD), using a Fundus Haploscope (Inatomi, 1980) and an Eye Movement Analyzing System (Kani, 1985). Excyclomovements and upward movements were observed in the deviating eyes in all cases, and incyclomovements in the fixating eyes in 6 cases. Sequential analysis revealed these movements to be "cycloversion". Vertical movements and cyclorotational movements were similar in their forms, but in some parts only the torsional movements were recognized. The rotatory nystagmus of patients' binocular vision efforts were almost purely rotatory, of the pendular type, and seemed to have congenital nystagmus characteristics. Many kinds of abnormal cyclorotational movements were found in these DVD cases. These movements were all version movements. Cyclorotational movements in DVD cases were thought to reflect abnormalities in the upper levels of the central nervous system. Abnormalities of the "cyclorotational movement center" were assumed in DVD.