Abstract: Alzheimer's disease(AD), dementia with Lewy bodies(DLB)and frontotemporal dementia (FTD)are the main type of neurodegenerative diseases, but the FTD and DLB are always confused with AD.Structural MRI, diffusion-weighted imaging and proton magnetic resonance spectroscopy have the potential to support the diagnosis of AD and the relative disease.Brain atrophy pattern, apparent diffusion coefficient and fractional anisotropy pattern, the distribution mode of N-acetylaspartate and myo-inositol in temporal lobe, hippocampus, pariet al lobe, frontal lobe could help to differentiate AD from FTD, DLB and those patterns are in accordance with the pathological changes.