Vestibular compensation deficits from unilateral labyrinthectomy(ULX) was investigated for 4 weeks in 21 Sprague-Dawley rats. Spontaneous nystagmus and eye movement which induced by sinusoidal rotation of the whole body at frequencies of 0.1, 0.2, 0.5 Hz in terms of vestibulo-oculomotor compensation and roll head tilt in terms of vestibulo-locomotor compensation were measured in the course of time following ULX. Also influence of flunarizine, a Ca²⁺ antagonist, injected into the 4th ventricle on the compensation of vestibular deficits was evaluated. Frequency of spontaneous nystagmus was 3.9±0.5 beats/sec(SD) immediately after ULX and declined to zero by 2 days. Roll head tilt was 33±10° just after ULX and decreased gradually with time, but it was not restored completely till 4 weeks. EMG activity of neck extensors in labyrinthectomized side was increased markedly following ULX and decreased gradually with time, however, it was still unbalance in both side till 7 days. In sinusoidal rotation following ULX normal pattern of eye movement induced by rotation toward lesion side appeared in 24 hours at rotation of 0.1 Hz and 12 hours at 0.2 Hz and 0.5 Hz. However, the vestibuloocular reflex(VOR) was not recovered completely normal till 3 weeks after ULX. Flunarizine injected into the 4th ventricle suppressed appearance of spontaneous nystagmus and VOR induced by sinusoidal rotation following ULX. These results suggest that VOR and vestibulospinal reflex are not compensated completely till 4 weeks after ULX, and flunarizine has a temporary effect on suppression of vestibular deficits.