The differentiation between central and peripheral vertigo is the main purpose of electronystagmography test. Abnormalities of saccades can be classified into disorders of the saccadic pulse, the saccadic step, or the way in which the pulse and step are matched. The one of pathologic saccadic eye movement is inappropriate saccades (saccadic intrusion). Saccadic intrusions include square-wave jerks, macrosquare-wave jerks, macrosaccadic oscillations, ocular flutter, and opsoclonus. When square wave jerks are large(10 to 40 degress) and are separated by intersaccadic intervals of about 100 msec, thses are called macrosquare-wave jerks. These have been observed in multiple sclerosis, oligopontocerebellar atrophy, and cerebellar hemorrhage. We have recently experienced a 67 year old male patient who had macrosquare-wave jerks eye movement by ENG test. The macrosquare wave jerks movement disappeared after diazepam therapy.