Abstract: Objective  To investigate the change of β-amyloid protein, tau protein and miR-related indexes of patients with vascular dementia and their correlation with severity of vascular dementia. 
Methods  A total of 79 patients with vascular dementia were selected as the observation group, and 79 healthy persons undergoing physical examination during the same period were selected as the control group. Then the serumβ-amyloid protein（Aβ1-40 and Aβ1-42）, tau protein（tau and p-tau） and miR-related indexes（miR-34a, miR-132 and miR-135） of the two groups were detected and compared, and the detection results of observation group with different severity of vascular dementia were compared. Then the correlation between those β-amyloid protein,tau protein, miR-related indexes and severity of vascular dementia was analyzed with Spearman rank correlation analysis. 
Results  The serum Aβ1-42, miR-132 and miR-135 of observation group were significantly lower than those of control group, while the serum Aβ1-40, tau protein and miR-34a were significantly higher than those of control group, suggesing significant differences（P＜0.001）. Those detection results of observation group with different severity of vascular dementia were compared, and there were statistically significant differences（P＜0.001）. The Spearman rank correlation analysis showed the serum Aβ1-42, miR-132 and miR-135 were negatively correlated with severity of vascular dementia, while the serum Aβ1-40, tau protein and miR-34a were positively correlated with severity of vascular dementia（P＜0.05）. 
Conclusion  The β-amyloid protein, tau protein and miR-related indexes of patients with vascular dementia show significantly abnormal state, and they all have close correlation to the severity of disease. Therefore, their detection value in the patients with vascular dementia is higher.

Key words: dementia, vascular, β-amyloid protein, tau protein