The use of fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS) and fluorescence excitation-emission matrix (EEM) systematically provide more comprehensive information on the changes in dissolved organic matter (DOM) composition and characteristic in water treatments. Therefore, this study aims to provide information on the molecular and spectroscopic characteristics of DOM in a full-scale drinking water treatment plant (DWTP) and summarize the effects of different treatment processes on DOM. This study sheds light on the molecular transformation of DOM in conventional treatments and advanced treatments.