Abstract: Abstract: Objective To explore the correlation of serum homocysteine (Hcy) level and cerebral apoplexy in the patients with type 2 diabetes mellitus (T2DM),providing a reference for the screening of stroke. Methods A total of 144 patients with T2DM were selected as observation group,30 healthy people were as healthy control group(group C).The patients of observation group were divided into two groups, group A without cerebral apoplexy and group B with cerebral apoplexy. The level of serum Hcy in all subjects was detected by enzymatic cycling assay and the carotid intima-media thickness (IMT) of all patients was checked using color Doppler echocardiography.The level of Hcy between observation group and control group as well as each subgroup of observation group was compared, and its correlation with IMT was also analyzed. Results The levels of Hcy and HbA1C in group A and B were higher than those in group C ,and they in group B were higher than group A （P<0.05).The levels of Hcy were positively correlated with HbA1c levels、age、gender、high density lipoprotein and creatinine (P＜0.05). The incidence of increased Hcy in the patients with carotid stenosis(IMT moderate and severe-stenosis groups ) was dramatically higher than in IMT mild and normal group（P=0.034）.The level of Hcy was IMT severe-stenosis group ＞IMT moderate-stenosis group ＞IMT mild-stenosis group（P＜0.001）. Pearson correlation analysis displayed that the level of Hcy was positively correlated with IMT(P＜0.001). Conclusion The level of Hcy can influence the incidence of cerebral apoplexy in patients with T2DM. The high level of Hcy is closely related to the occurrence and progression of atherosclerosis ,conducive to early prevention，intervention and prognostic assessment of cerebral apoplexy.

Key words: diabetes mellitus, cerebral apoplexy, homocysteine, atherosclerosis, carotid artery stenosis