Aβ is the major components of amyloid plaque deposition in the brain, and is considered to be the initiating factor for the pathogenesis of Alzheimer's disease(AD). β-amyloid precursor protein cleaving enzyme 1 (BACE1) is one of the important enzymes in the Aβ production. The process of maturation and expression of BACE1 is regulated by a variety of factors. Some of the pathological changes of early onset of AD such as ischemia, hypoxia, inflammation and stress are considered to be BACE1 related. Many BACE1 and Aβ related cytokines in the fluids may become potential biomarkers, which would provide ideas for early clinical diagnosis of AD.