Abstract: Alzheimer disease (AD) is a neurodegenerative disease. It is difficult to make an early diagnosis because it is insidious onset. One of the neuropathological hallmarks of AD is the formation of senile plaques, which is composed of fibril amyloid β-protein (Aβ). And amyloid deposition is an early event on the path to dementia. N-¹¹C methyl-2-4′-methylaminophenyl-6-hydroxybenzothiazole(¹¹C-PIB) is a specific molecular probe of Aβ, which could monitor the change of fibril Aβ non-invasively, dynami-cally and quantitatively. In order to aid early diagnosis, screen the population for antiamyloid therapies and monitor the therapeutic effects, it is urgent to elucidate the PIB characteristics of distribution at different stage of AD. Therefore, the application of ¹¹C-PIB PET in AD in the latest years will be summarized.