Aim To investigate the relationship between coronary artery lesion and carotid atherosclerosis (CAS), cerebral infarction in patients with coronary heart disease. Methods 319 patients with coronary heart disease diagnosed by coronary angiography were selected. The patients with coronary heart disease were divided into four groups according to the degree of coronary artery lesion. The differences of CAS grade score, Crouse plaque score, plaque number, and cerebral infarction incidence were compared in each group. In addition, 319 cases of coronary heart disease were divided into two groups:cerebral infarction group and non cerebral infarction group, according to whether there was cerebral infarction or no. The differences of carotid plaque character, CAS grade score, Crouse plaque score, plaque number were compared between two groups. Results The CAS grade score, Crouse plaque score, plaque number in 3 branchs lesion group and left main coronary lesion group were significantly higher than those in 1 branch lesion group and 2 branchs lesion group (P＜0.05). The incidence of cerebral infarction was 27.53% in 3 branchs lesion group, and the incidence rate was 38.27% in left main coronary lesion group. Cerebral infarction case was not found in 1 branch lesion group and 2 branchs lesion group. The incidence of unstable plaque in the cerebral infarction group was significantly higher than that in the non cerebral infarction group (90.00% vs 46.02%, χ²＝6.2949, P＜0.05). Conclusions In patient with coronary heart disease, the more serious the coronary artery lesion, the more severe the CAS, the higher the incidence of cerebral infarction. Carotid unstable plaque is more likely to induce cerebral infarction.