Xenoestrogens are chemicals with diverse structure that mimie estrogen Bisphenol A, a monomer of poIycarbonate and epoxy resins, has been detected in canned food and human saliva Bisphenol A stimulate cell proliferation and induce expression of estrogen- response genes in vitro The purpose of the this study was to evaluate cell proliferation of bisphenol A in the presence of a rat liver S9 mix contaning cytochrome P450 enzymes and Cu (II) The fragmentation of intact DNA, a parameter of apoptotic cell death, was evaluated quantitatively by diphenyladmine reaction method Bisphenol A induced apoptotic cell death in a dose-dependent manner The effest of radical scavenger on the apoptotic cell death induced bisphenol A was investigated The DNA fragmentation induced by bisphenol A was significantly inhibited by addition of radical scavenger to the culture medium This indicated that elevated oxidative stress caused by imbalance between the production and removal of free radical occurred in cells Taken together, these results suggest that free radical reacts with Cu(II) leading oxidative stress