Synchronous fluorescence spectroscopy and 3-dimensional excitation emission matrices spectra (3DEEM) were used to study the composition variation of dissolved organic matter (DOM) in landfill leachate in the adsorption process with 717 resin. The synchronous fluorescence spectra showed fluorescence intensities of longer wavelength went down greatly while those of shorter wavelength went up in the first 10 min, then there were little changes. 3DEEM results indicated that there were two fulvic-like fluorescence peaks, whose intensities decreased dramatically, the peak intensities ratio (IUV/IVis) also decreased, and the blue shifts of emission wavelengths took place obviously with the time rising. It was indicated that the adsorption rate of DOM by 717 resin was fast, and the main adsorbed DOM had higher molecular weight and higher degree of complexity, which was potential to facilitate subsequent bio-treatment.