Skew deviation is an acquired common vertical strabismus. The clinical manifestation includes head tilt， eye rotation and subjective vertical visual tilt. In these patients， the subjective visual world tilts in the vertical direction. In order to restore vertical positioning， the eyes and head rotate in the direction of the subjective visual world. The etiology of this disease is an injury to the vestibular-ocular reflex pathway. This article reviews the etiology， clinical manifestations and clinical types of skew deviation， and differentiates it from superior oblique palsy. The objective of this paper is to increase awareness of skew deviation among ophthalmic clinicians and to avoid a misdiagnosis of superior oblique palsy or ignore possible lesions in the utricular otolith or central nervous system.