In this work, the degradation efficiencies of bisphenol A (BPA) by Fenton reaction were comparedsystematically with varying cyclodextrins. The results showed that the removal rate of BPA displays aconsiderable increase by Fenton reaction in presence of b-cyclodextrin (b-CD) and its derivatives. Specifically, 98 2% and 89 2% of BPA was removed with carboxymethyl-b-cyclodextrin (CMCD) andb-CD, respectively. Additionally, to understand the reaction mechanism, the structure activity ofcyclodextrins with substrate and the kinetic of Fenton reaction with cyclodextrins have beeninvestigated. Results showed that the structure activity was the major role for cyclodextrins in thissystem.