Vulnerable plaque refers to the plaque with poor stability in the arterial wall, which is easy to rupture and fall off, leading to the formation of in situ thrombus or multiple microemboli. Carotid atherosclerotic vulnerable plaque is the main pathogenic mechanism of ischemic stroke, and carotid plaque vulnerability increases the occurrence of cerebral ischemic events. Therefore, early identification of vulnerable plaques is of great significance for intervening high-risk factors for stroke and improving stroke prognosis. In addition to various imaging techniques, circulating biomarkers provide an adjunct to the identification of vulnerable carotid plaques. This article reviews previous studies, discussing novel biomarkers capable of identifying carotid vulnerable plaques.