Abstract: Biological treatment of BPA by activated sludge was investigated to get the treatment effect,degradation kinetics and decontamination mechanism.Acclimation has great influence on treatment effect,and the removal rate of BPA can be more than 90% by acclimated sludge.Monod coefficients were measured with biomass from a fed batch reactor at steady state,while q___(max)=0.35 d~(-1),K_s=15.5 mg/L.So,the degradation velocity is slow.Biological degradation is the major removal pathway at activated sludge treatment of BPA.Where BPA is not accumulated in excess sludge.