Background Dexmedetomidine(DEX) is a novel and highly selective alpha-2-adrenergic agonist with sedative,analgesic and anxiolytic properties. The sedation it provides is characterized by an easy and quick arousal and minimal respiratory depression. Traumatic brain injury patients often need appropriate sedation to reduce the cerebral oxygen consumption，and prevent secondary brain injury. Ideally they should be waken up easily for clinicians to determine their state of mind. Objective The aim of this review is to outline the research advances of DEX in traumatic brain injury and provide practical guidance for clinical practice. Content From the aspects of mechanism of action，effect on brain damage and clinical application, we reviewed the influences of DEX on traumatic brain injury. Trend DEX offers neuroprotective properties by providing sedation, anxiolysis, anti-apoptosis and so on. It is characterized by causing no respiratory depression and no effect on determining the state of mind. All of these properties make it a promising sedative for traumatic brain injury. However there is little research of DEX on animal model as well as patients of traumatic brain injury, so we still do not know the comprehensive function of DEX on animal model as well as patients of traumatic.