Abstract： Objective To investigate the clinical and imaging features of patients with Alzheimer' s disease (AD) and vascular dementia (VaD) and find an effective method to make differential diagnosis between the 2 entities. Methods One hundred and sixty-two patients with dementia,admitted to our hospital from August 2006 to June 2011, and 42 patients with dementia found from community epidemiological survey were chosen in our study; their clinical data were retrospectively collected and analyzed; in these patients,114 patients were with AD and 90 patients were with VaD.Mini Mental State Examination (MMSE) was performed on these patients and the cognitive competence,behavioral symptoms and imaging data of these patients were analyzed and compared. Results More female,higher education level and longer course of disease in patients with AD were noted as compared with those in patients with VaD (P＜0.05); the scores of attention and calculation in patients with VaD were obviously lower than those in patients with AD (P＜0.05); the scores of short-term memory,retelling and reading comprehension in patients with VaD were obviously higher than those in patients with AD (P＜0.05); the happening of repeated convergence behavior in patients with AD was much more often than that in patients with VaD (P＜0.05); patients with AD had higher ratio of shrinking hippocampus than patients with VaD, and the incidence of vascular disease in the brain of patients with VaD was significantly higher than that of patients with AD (P＜0.05). Conclusion Substantial differences on clinical and imaging features exist in AD and VaD patients,which can be attributed to the differences of lesion nature and distribution,as well as the underlying pathophysiological procedures of each disease.