E-beam degradation of bisphenol A (BPA) was carried out, under reductive condition of ethanol-water solution and oxidative condition of acetonitrile-water solution. The degradation efficiency is higher in oxidative condition than that in reductive condition, and increases with the dose but decreased with increasing initial concentration. The BPA radiolysis follows the pseudo-first-order kinetics. Adding H₂O₂, or neutral condition, does not benefit BPA degradation in oxidative conditions. Pulsed radiolysis was used to investigate mechanism of the BPA radiolysis. The rate constant for BPA reaction with ^·OH (1.85×10¹⁰ L·mol^–1·s^–1) is about an order of magnitude higher than that with e^–_aq (1.80×10⁹ L·mol^–1·s^–1). The degradation products were analyzed by ion chromatograph. Smaller molecules such as formic acid and acetic acid were detected, indicating that ^·OH attacks the BPA molecule. The work is of significance for the practical E-beam treatment of waste water containing BPA.