In this study, ibuprofen(IBP) degradation by the photochemical (UV/S2O8 ). The pseudo-first-order degradation rate constants were in the order of 10 -1 to 10 -5 min -1 depending on each processes. The synergistic effect of IBP degradation in UV/S2O8 2-and US/S2O8 2-processes could investigated, due to the generation of SO4 -radical. This result can confirm from the produced H2O2 and SO4 2-concentration in each processes. IBP degradation rate affected by the S2O8 2-dosage, temperature, power and anion existence parameters. In particular, IBP degradation rate increased with the increase of the temperature (60℃) and applied power density (UV:40±5 W/L, US:90±5 W/L). On the other hand, anions effect on the IBP degradation was negative, due to the anion play as a the scavenger of radical.