Objective:To evaluate the vestibular function of motion sickness. Method:VNG, which tests the vestibular function of horizontal semicircular canal,and CPT, which tests vestibulospinal reflex and judge proprio-ceptive,visual and vestibular status, were performed in 30 motion sickness pations and 20 healthy volunteers(control group). Graybiel score was recorded at the same time. Result:Two groups' Graybiel score (12. 67±11. 78 vs 2. 10±6. 23;rank test P<0. 05),caloric test labyrinth value [(19. 02±8. 59)°/s vs (13. 58±5. 25)°/s ;t test P< 0. 05],caloric test labyrinth value of three patients in motion sickness group exceeded 75°/s. In computerized pos-tourgrphy testing(CPT) , motion sickness patients were central type(66. 7%) and disperse type(23.3%);all of contral group were central type. There was statistical significance in two groups' CTP area, and motion sickness group was obviously higher than control group. While stimulating vestibulum in CPT, there was abnormality (35%-50%)in motion sickness group and none in contral group. Generally evaluating CPT,there was only 2 pro-prioceptive hypofunction,3 visual hypofunction, and no vestibular hypofunction, but none hypofunction in contral group. Conclusions Motion sickness patients have high vestibular susceptible, some with vestibular hyperfunction. In posturography,a large number of motion sickness patients are central type but no vestibular hypofunction, but it is hard to keep balance when stimulating vestibulum.