Objective To compare the cognitive function of patients with carotid stenosis combined with white matter lesions (WML)after carotid artery stenting (CAS). Methods Total 166 patients with carotid artery stenosis were collected.According to MRI imaging,30 patients with no white matter lesions were included in the control group and 136 patients with white matter lesions were included in the white matter lesions group. They were treated with carotid artery stenting and underwent evaluation on the safety and efficacy of perioperative surgery. CAS failed in two patients because of the inability of guidewire crossing in WML group. Two patients died after CAS (one for cardiac death and one for traumatic accident) in WML group. 162 patients received 1 year follow-up. Cognitive function was assessed before and after CAS. Results Before CAS,WML group's MMSE, digit span forward/backward test, verbal fluency test and MoCA scores (21.8±3.3、6.3±2.1、4.1±1.0、15.1±3.6、20.6±3.1) were lower compared with control (24.3±3.9、7.3±2.6、4.7±1.8、17.7±5.2、22.7±4.2) and ADAS-Cog score was higher compared with control ((15.1±3.3) vs.(12.7±3.3)), P=0.000、0.026、0.039、0.012、0.000、0.011.Three months after CAS,the MMSE,digit span forward test and MoCA scores (23.7±3.6,7.5± 2.4, 23.1±6.9) was higher significantly than those before treatment (21.8±4.3, 6.3±2.09, 20.6±4.13), P<0.05.And the scores of ADAS-Cog was lower((13.2±4.)vs.(15.1±4.3),P<0.05).The scores of digit span backward test in 6 months after treatment was significant higher than those before treatment (4.9 ±2.8,4.1 ±2.2,P<0.05). After 1 year of CAS, the improvement in scores of MMSE, digit span forward test, ADAS-Cog and MoCA in patients with carotid stenosis complicated with WML(3.5±1.3,1.6±0.6,-2.6±0.8,3.6±1.1)was higher significant than control(2.7±1.8, 1.2±0.8, -2.0± 1.3, 2.7 ±1.5),P<0.05. Conclusion CAS can improve cognitive function in Patients with carotid artery stenosis complicated with WML than those who without WML.