The liquid-phase hydrogen peroxide catalytic oxidation of p-nitrophenol was performed with an Fe-III-resin catalyst. The conversion and mineralization of p-nitrophenol was effectively achieved at mild reaction conditions with the FeIII-resin catalyst. It was found that the oxidant concentration, pH, and temperature dominated the degradation rate of p-nitrophenol. The denitration pathway of p-nitrophenol was proposed, in which the concentration of H2O2 and temperature showed strong influence on the conversion of nitrite to nitrate. To study the factors influencing the denitration of p-nitrophenol, a comparable kinetic study was attempted to know the possible denitration pathway of p-nitrophenol. The results of this investigation indicated that denitration was the possible step occurring with the decomposition of p-nitrophenol.