The degradation kinetics and reaction pathway of acetaminophen in aqueous solution were investigated in a UV/H_2 O_2 batch photo-oxidation reactor. The effects of the important factors including the dosage of H_2 O_2,initial pH value,UV light power as well as coexisting anions( HCO_3~-、NO_3~-) on the degradation rate of acetaminophen were evaluated. The experimental results showed that acetaminophen was removed effectively using UV/H_2 O_2,and the degradation of acetaminophen could be well fitted with the p...