The spatial patterning of each neurodegenerative disease relates closely to a distinct structural and functional network in the human brain. This talk will mainly describe how brain network-sensitive neuroimaging methods such as resting-state fMRI and diffusion MRI can shed light on brain network dysfunctions associated with pathology and cognitive decline from preclinical to clinical stage of neurological disorders. I will first present our findings from two independent datasets on how amyloid and cerebrovascular pathology influence brain functional networks cross-sectionally and longitudinally in individuals with mild cognitive impairment and dementia. In the second part, I will describe our recent work on brain structural network and white matter microstructure. Evidence on longitudinal structural and functional network changes underlying cognitive decline in older adults will be presented. Lastly, I will touch on some new data on how individual-level brain network integrity contributes to behavior and disease progression using machine learning and computational approaches. These findings underscore the importance of studying selective brain network vulnerability using a longitudinal design. Further developed, multimodal network-specific imaging signatures will help reveal disease mechanisms and facilitate early detection, prognosis and treatment search of neuropsychiatric disorders.