Phenol degradation with a UV/Ag+/K2S2O8 advanced oxidation process (AOP) was studied in a batch photolytic reactor. The UV irradiation source was a low-pressure mercury vapor lamp that was axially centered and was immersed in the phenol solution. In the UV/ K2S2O8 and Ag+/K2S2O8 system, the degradation of phenol was inefficient with an low concentration K2S2O8 at ambient temperature, and only around 26% and 23%of the phenol was degraded in 3 h , respectively. In the UV/Ag+/K2S2O8 oxidation process, persulfate (S2O82-) was activated by UV irradiation and Ag+ catalysis to produce powerful oxidants, SO4– •.The effects of K2S2O8 concentration, UV irradiation time and Ag+ concentration on the oxidation had been investigated. The experimental results indicated that optimum K2S2O8 concentration was 0.37mmol/L, and Ag+ concentration was 0.185 mmol/L. Phenol and chemical oxygen demand (COD) reduction was analyzed to determine the efficiency of the UV/Ag+/K2S2O8 process in mineralization, where we obtained 77% phenol reduction, and 65% COD reduction, respectively . The efficient mineralization of phenol is based on the in situ formation of the strong oxidant sulfate anion radical.