The objectives of this study were as follows: (1) to investigate the alteration in the DBP formation during post chlorination after SO4•- and HO• oxidation from NOM and typical model compounds; (2) to investigate the effects of the treatment time, persulfate dosage and water matrices on the DBP formation from NOM by UV/persulfate. The selected model compounds were typical aromatic compounds of benzoic acid (BA) and resorcinol as well as typical organic nitrogen compounds of methylamine (MA), dimethylamine (DMA) and glycine.