A new UV-VIS Spectrophotometric method for the determination of BPA in plastics was established based on its inhibitory effect on acridine orange oxidation which is caused by hydroxyl radical from Fenton reaction in acid medium. The influences of acidity, concentration of reactants, reaction time, reaction temperature, and foreign ions and distractors were found by data mining, and the optimum reaction conditions were established based on data analysis result. The results which were provided by optimal reaction conditions show that there was a linear relationship between the absorption change of AO and the concentration of BPA with the linear regression equation as ΔA=0.643lgc-0.544.The method was used in the determination of BPA in 4 samples, the relative standard deviations were 1.64 %～3.04% and the recoveries were 95. 0%～104.3% with satisfactory results