Abstract: Abstract: To search the association between the expression levels of APP and PS1gene and Alzheimer’s disease(AD), 45 patients with AD、25 patients with VD (vascular dementia,VD) and 60 healthy controls were involved. Real-time quantitative PCR using SYBR Green I dye was performed with ABI PRISM 7900 HT(Applied Biosystems). In healthy controls、AD cases and VD cases, the APP gene expression levels are 0.026±0.005amol/ug cDNA、0.044±0.006amol/ug cDNA and 0.072±0.013 amol/ug cDNA, the PS1 gene expression levels are 0.026±0.004 amol/ug cDNA、0.051±0.011amol/ug cDNA and 0.039±0.005amol/ug cDNA, respectively. Both APP and PS1, the expression levels are all significantly increased rather in AD cases or in VD cases(APP, AD vs Control, t=2.639, P<0.01, VD vs Control, t=3.028，P<0.01; PS1, AD vs Control, t=2.173， P<0.05, VD vs Control, t=2.012，P<0.05). It seems that the enhanced APP and PS1 gene expression have the association with dementia but not especially with AD.