Abstract: The disease progression of carotid atherosclerosis is closely related to the development of stroke. Improvement of plaque stability is particularly important for reducing the incidence and mortality of stroke. This review systematically reviewed the background of carotid atherosclerotic plaque, the concept of plaque stability, the relationship between carotid artery stenosis and plaque stability, and the pathogenesis of plaque stability. Finally it explained the imaging methods in evaluation of plaque stability.