Objective To investigate the diagnostic value of combining video nystagmography and video head impulse test(vHIT)in determining the nature of acute vestibular syndrome(A VS).Methods A total of 387 patients with AVS were enrolled and divided into central group(central vas-cular,n=181)and peripheral group(vestibular peripheral,n=206).Patients underwent examina-tions using VOG and vHIT,and parameters were recorded.Results In video nystagmography re-sults,the proportion of patients with type Ⅲ curve in stable tracking test and recoil in saccade test in the central group was significantly higher,while the proportion of patients with unilateral weakening of nystagmus gain in positional nystagmus test and swivel chair rotation-scram test was significantly lower than that in the peripheral group(P＜0.05).The proportion of vHIT abnormity in the central group was significantly lower,and the low-frequency level vestibular ocular reflex(VOR)gain values was significantly higher than that in the peripheral group(P＜0.05).Multivariate logistic regression re-vealed that type Ⅲ curves(OR=1.859,95％CI,1.235 to 3.032,P＜0.001)and low-frequency level VOR gain values(OR=1.524,95％CI,1.102 to 2.231,P＜0.001)were associated with central vascular AVS,whereas abnormal vHIT(OR=0.523,95％CI,0.321 to 0.899,P＜0.001)was associated with vestibular peripheral AVS.Receiver operating characteristic(ROC)curve analy-sis indicated that the area under the curve(AUC)for diagnosing central vascular versus vestibular peripheral AVS using type Ⅲ curves,low-frequency level VOR gain values and abnormal vHIT was 0.903(95％CI,0.812 to 0.956,P＜0.001).Conclusion Combining video nystagmography with vHIT is an important tool for rapid and accurate differentiation of the etiology of AVS.