Abstract: The filler is the main medium of constructed wetland, especially the bed of subsurface flow constructed wetland. It is the main carrier of wetland physical, chemical and biological reaction, and has a decisive influence on the removal of contaminants. The literature on the sources, physical properties and chemical composition of common substrate media and practical applications were reviewed, including natural product fillers, industrial/agriculture by-product fillers and synthesis fillers. The mechanisms of substrate media for contaminants removal in water were summarized, including adsorption-sedimentation, ion exchange, slow-release carbon source- electron donor, oxidation-reduction. The removal ability of nitrogen, phosphorus and heavy metal pollutants in subsurface flow wetland was discussed, and the removal effect of different fillers was compared. Finally, the selection of subsurface constructed wetland fillers and prospects for strategy research in the future were prospected, in order to provide scientific guidance and theoretical basis for the further development of constructed wetland and wastewater treatment technology.