Iodoform (CHI3) is an emerging disinfection by-product (DBP) that may be formed during pre-oxidation or disinfection processes in drinking water treatment. Degradation kinetics, modeling and mechanism of CHI3 by combined UV/chlorine advanced oxidation processes (AOPs) were studied in this manuscript. CHI3 was effectively removed by UV/chlorine process with the reactions followed pseudo-first order kinetics. The contributions of direct UV photolysis as well as indirect photolysis (hydroxyl radicals (OH) to CHI3 degradation during UV/chlorination under different experimental factors were investigated and determined as 20.3% and 79.7% at pH 5 to 97.1% and 2.9% at pH 9, respectively. Chlorine dosage and CHI3 concentration had slight effects on the contributions of different degradation pathways. NOM and bicarbonate have negative effects on CHI3 degradation. The degradation model of CHI3 during UV/chlorine processes was established, and the satisfactory match of the model calculation results and the experimental data were found. The reaction rate constant between CHI3 and UV light as well as CHI3 and OH were determined as 3.43×10−3s−1 and 7.7×109M−1s−1, respectively. On the basis of the iodine species (such as IO3−, HOI, I2 and I3−) mass balance analysis, the degradation pathways of CHI3 were proposed and IO3− contributed 13.7% of the total liberated iodine species during UV/chlorination. These results demonstrated that UV/chlorination process is a promising AOP technology for the treatment of water containing CHI3.