Objective:To explore the correlation between serum homocysteine(Hcy),score of carotid plaque vulnerability and white matter lesion,cognitive dysfunction in elderly patients with cerebral small vascular disease(CSVD).Methods:A total of 126 elderly patients with CSVD were enrolled as the research objects.According to cognitive function level,they were divided into impair-ment group(n=66)and non-impairment group(n=60).The general clinical data,level of serum Hcy,scores of carotid plaque vul-nerability,white matter lesion grading(Fazekas)and cognitive function[Mini-Mental State Examination(MMSE)]in the two groups were compared.According to the Fazekas score of all patients,they were divided into a group with white matter lesions and a group with normal white matter.The serum Hcy levels and carotid plaque vulnerability scores of the two groups were compared,the correlation be-tween level of serum Hcy,score of carotid plaque vulnerability and Fazekas score and MMSE score was analyzed.Results:Compared with non-impairment group,age,proportions of hypertension and dementia family history,levels of serum D-dimer and Hcy,scores of ca-rotid plaque vulnerability and Fazekas were higher in impairment group(P＜0.05),MMSE score was lower(P＜0.05).Compared with the normal white matter group,the level of serum Hcy and score of carotid plaque vulnerability were higher in the white matter le-sion group(P＜0.05).The level of serum Hcy and score of carotid plaque vulnerability were positively correlated with Fazekas score,while negatively correlated with MMSE score(P＜0.05).Conclusion:The level of serum Hey and score of carotid plaque vulnerabili-ty are positively correlated with white matter lesion and cognitive dysfunction in elderly patients with CSVD.