Amyloid β protein (Aβ) is known to increase oxidative stress in nerve ceils,leading to apoptosis that is characterized by free radical formation and lipid peroxidation.The neurodegenerative diseases such as Alzheimer(A)s disease (AD)are characterized by large deposits of Aβ in the brain.In our study,neuronal protective effects of green tea along with wateractivity (0.81) and storage period (fresh~4 weeks) were investigated against Aβ-induced cytotoxicity in neuron-like PC 12 cells.