Aim To explore the relationship between serum levels of anti-β2-glycoprotein 1 （anti-β2-GP1） antibody and carotid atherosclerosis （CAS） and its risk factors in patients with cerebral infarction. Methods A total of 303 patients of anterior circulation cerebral infarction were recruited and carotid arteries were measured by vascular Doppler ultrasound instrument. According to the presence of carotid atherosclerotic plaque and the degree of carotid stenosis, the 303 patients were divided into three groups: no plaque and stenosis group （group A） with 79 cases, plaque but having no stenosis group （group B） with 98 cases, plaque and stenosis group （group C） with 126 cases. Among the 126 patients of carotid stenosis, case number of 1, 2, 3 and 4 grade of carotid stenosis was 41, 34, 30 and 21 respectively. The serum levels of anti-β2-GP1 antibody were measured by ELISA, enzymatic was used to measure levels of blood sugar, triglyceride and total cholesterol, the direct method was used to measure the serum levels of low density lipoprotein cholesterol （LDLC） and high density lipoprotein cholesterol （HDLC）. Results The serum level of anti-β2-GP1 antibody in patients of groups A, B, C was 16.02±16.23 kRU/L，21.43±16.15 kRU/L，34.89±19.15 kRU/L respectively. Serum level of anti-β2-GP1 antibody between patients of group B and C was significantly higher than group A （P＜0.05 or P＜0.01）, serum level of anti-β2-GP1 antibody was the highest in patients of group C. As carotid atherosclerosis stenosis progressed, serum level of anti-β2-GP1 antibody increased. Serum level of anti-β2-GP1 antibody was positively associated with LDLC. Conclusions Serum levels of anti-β2-GP1 antibody play a role in the occurrence and development of carotid stenosis and LDLC was the independent risk factor of increased serum level anti-β2-GP1 antibody. Serum anti-β2-GP1 antibody may be used as one of the serum biochemical indexes of carotid artery atherosclerosis.