Objective: This study was to demonstrate the biomarkers (NSE,MMP9,S100B,HO-1,CO) in serum for their correlation with reperfusion after carotid artery stenting (CAS). Methods: In this study, a total of 44 patients who were diagnosed with carotid artery stenosis (symptomatic/ asymptomatic stenosis≥70%) by Digital Subtraction Angiography (DSA) and underwent CAS successfully, were selected as the operation groups. The patients’ blood samples were collected at three different time points: T1, prior to operation; T2, next morning after operation (24 hours); T3, three days after operation (72 hours); The second group of 30 patients, who were excluded for carotid artery stenosis by DSA, were assigned to be the control group; Blood samples of these patients were collected at T1. The concentrations of NSE, S100B, MMP9, HO-1 and CO in serum from patients of both groups were detected by ELISA. Results: (1) There was no significant difference between the control group and the operation group at T1 (P>0.05) on their concentrations of NSE, S100B, MMP9, HO-1 and CO in the serum. (2) All of the operations were implanted in stents successfully without complications and the reperfusion improved after CAS. The concentrations of NSE, S100B, MMP9 and CO in the serum decreased gradually.(T1: 378.53±187.74MU/ml, 20.04±9.27ng/ml, 3.28±1.62ng/ml, 2.21±1.98umol/l respectively; T2: 302.65±160.46MU/ml, 16.45±8.95ng/ml, 2.81±1.63ng/ml, 1.49±1.10umol/l respectively, T1 vs T2: P<0.01; T3: 280.60±159.22MU/ml, 12.62±8.32ng/ml, 2.59±1.55ng/ml, 1.22±1.04umol/l respectively,T1 vs T3: P<0.01). (3) The serum concentrations of HO-1 in the T2 increased when compared with T1 (P<0.05) and obviously increased in the T3 when compared with T1 (P<0.01). Conclusions: We concluded that the concentrations of NSE, S100B, MMP9 and CO in serum decreased with the improvement of cerebral reperfusion after CAS. NSE, S100B, MMP9 and CO can be used as biomarkers to evaluate the improvement of reperfusion after CAS. What’s more, the changes of HO-1 after CAS may be associated with hyper-perfusion syndrome. Key words: NSE; S100B; MMP9; CO; HO-1;reperfusion; carotid artery stenting