Wake-up stroke （WUS） refers to the stroke which do not have neurological system symptoms during sleep， but is found after waking up， by patients or witnesses. It takes 14.3%-29.6% proportion of acute ischemic stroke. Because of the uncertainty of the onset time， it is usually not suitable for the specific treatment of acute ischemic stroke in time window. In recent years， with the development of multimodality CT （MCT） and magnetic resonance imaging （MRI） in the recognition of ischemic stroke infarct and ischemic penumbra， there is increasing evidence that intravenous thrombolysis， mechanical thrombolysis and other treatment regimens benefit WUS patients better. A review of the pathophysiological mechanism， risk factors， clinical and imaging characteristics， and the latest development of treatment plan of WUS is presented in this paper.