CeO2/TiO2　catalysts　were　fabricated　by　dry　ball　milling　in　the　presence　or　absence　of　an　organic　ligand.　It　was　found　that　the　catalysts　prepared　by　ligand-assisted　ball　milling　exhibited　high　NH3-SCR　activities　due　to　the　interaction　between　cerium　ions　and　ligand　molecules　resulting　in　good　dispersion,　a　high　Ce3+　ratio　and　high　reducibility　of　cerium　species.