Photodegradation of o-cresol in water has been investigated using hydrogen peroxide as an oxidant along with ultra violet lamps. The synergistic effect of H(2)O(2) and UV light was found to be effective to decomposition of o-cresol in water. The effects of wave length of UV light, initial concentration of o-cresol, hydrogen peroxide dose and initial solution pH on photodegradation rate of o-cresol were systematically examined. Degradation of o-cresol with UV-C lamps (wavelength of 254 nm) was more significant than that with near-UV black light lamps (wavelength of 352 nm). The optimal solution pH was around 5 being the natural pH of the solution. The efficiency of o-cresol degradation increased as initial o-cresol concentration decreased. There was the optimal H2O2 dose being around 150 mM when the initial o-cresol concentration was 0.93 mM. Based on the experimental results, a kinetic model for the photodegradation of o-cresol by H(2)O(2)/UV has been developed. The model could simulate the experimental results reasonably.