Responsive characteristics of vestibulo-ocular reflex,vestibulo-spinal reflex and postural equilibrium of cats under linear acceleration,before and after plugged semicircular canal operation were studied.After bilateral canal plugged,no significant changes of power spectra and relative gain of otoliths-ocular reflex were found,and similar responsive patterns of H wave of spinal reflex under different linear acceleration were appeared.After unilateral canal plugged vestibulo-ocular reflex showed a significantly asymmetry and changes of H wave were not related with linear acceleration.It was that asymmetry of canal function impacted significantly on symmetric functions of otoliths.The causes of space vestibular dysfunction were discussed.It was suggested that the potention asymmetry of otoliths and semicircular canal function would be the primary factor of space vestibular dysfunction.