This paper introduces the UV-H2O2 process for removal of dimethyl phthalate (DMP) in drinking water. According to the experimental results, the DMP can not be effectively removed by UV radiation alone, while quite good results can be achieved by UV-H2O2 process. With the initial concentration of DMP about 5.1496 μmol·L-1 (l.0 mg·L-1), its removal efficiency reached 91.96% under the condition that the intensity of UV radiation is 133.9 μW·cm-2, the dosage of H2O2 20 mg·L-1 and reaction time 60 minutes. Meanwhile, a newly oxidation byproduct with stronger polarity than that of DMP can be detected before DMP peaks from HPLC during oxidation. A kinetic model related to DMP removal and byproducts is built to perfectly simulate DMP degradation in UV-H2O2 process.