Aim To study the relationship between serum homocysteine （Hcy） and carotid plaque in patient with aged cerebral infarction. Methods 165 aged （≥70） cerebral infarction patients from July 2008 to October 2010 were selected. The serum levels of Hcy determine and carotid artery ultrasonography technique were performed for all patients. The relationship between carotid plaque and serum homocysteine of divided groups were compared. Results The level of Hcy was higher in patients with carotid plaque （22.65±6.17 μmol/L） than that in patients without carotid plaque （12.20±2.52 μmol/L P＜0.05）. The level of Hcy was higher in patients with soft carotid plaque （26.71±8.17 μmol/L） than that in patients with compound carotid plaque （20.31±7.06 μmol/L P＜0.05），the level of Hcy was higher in patients with compound carotid plaque than that in patients with strong carotid plaque （19.67±3.80 μmol/L P＜0.05）. Logistic regression analysis showed that Hcy was an independent risk fator of carotid plaque （P＜0.05）. Conclusions There was a severitily correlation beween Hcy level and carotid plaque in aged cerebral infarction patient, and Hcy level is an independent risk fator of carotid plaque.