Unilateral labyrinthectomy(ULX) causes vestibular symptoms, such as nausea, vomiting, vertigo, spontaneous nystagmus, and head deviation, but some of these symptoms diminish with time in a process of behavioral recovery known as vestibular compensation. In order to investigate the effects of flunarizine and MK-801 on the compensation of vestibuloocular reflex (VOR), spontaneous nystagmus, eye movement induced by sinusoidal rotation of the whole body, and electrical activity of the medial vestibular nuclei were measured following ULX in Sprague-Dawley rats. Spontaneous nystagmus following ULX disappeard by post-operative 48 hours in control group, by 24 hours in flunarizine treated group, and by 12 hours in MK-801 treated group. On sinusoidal rotation of the whole body at 0.1 Hz, eye movement induced by rotation toward the lesioned side recovered the normal pattern of VOR after 24 hours in control group, on 12 hours in flunarizine treated group, and on 6 hours in MK-801 treated group. Also, directional preponderance of VOR decreased to less than 20% by 48 hours in control group and in flunarizine treated group, and by 24 hours in MK-801 treated group. Field potential evoked by stimulation of the vestibular system was composed of 3 waves, such as P, N1, N2 wave, whose amplitude was decreased by flunatizine or MK-801. Spontaneous activity in the medial vestibular nuclei was suppressed by flunarizine or MK-801, however, the activity of the ipsilateral type I cell decreased by ULX was increased by MK-801. These results suggest that flunarizine or MK-801 acting on the intact vestibular nuclei as well as the lesioned nuclei ameliorates the compensation of VOR following ULX by accomplishing the symmetry of electrical activities in the bilateral vestibular nuclei.