Aim of the present research work was to study the relationship between the degree of dementia and the serum levels of homocysteine(Hcy), high-sensitive C-reactive protein(hs-CRP), D-Dimer and vascular dementia(VaD) of patients, and to investigate the mechanism of Hcy, hs-CRP and D-Dimer in the vascular dementia. Subjects were divided into normal group and VaD group. CRP and D-Dimer protein of each sample were detected by nephelometry method, and the serum Hcy level was detected by Fluorescent labeling immunoassay method. Compared with the normal control group, Hcy, hs-CRP and D-Dimer in VaD group were significantly higher than that of control group, and the difference was statistically significant. Linear correlation analysis showed a negative association between Hs-CRP, Hcy and MMSE score. There was no correlation between the levels of D-Dimer and the MMSE score. Hcy, hs-CRP and D-Dimer are involved in the pathogenesis of vascular dementia (VAD), There is a significant correlation between the severity of vascular dementia and Hcy and Hs-CRP.