The present study compared the adsorption and removal efficiency of ammonia nitrogen by titanium slag，steel slag and blast furnace slag.The results showed that compared to the Freundlich model，the Langmuir isothermal adsorption model could be used to fit ammonia nitrogen adsorption；the most adsorption capacity of three substrates for ammonia nitrogen was steel slag.Adsorption types of steel slag and titanium slag were physical adsorption and chemical adsorption，but the adsorption type of blast furnace slag was physical adsorption.Removal rates of three substrates for ammonia nitrogen increased with substrates content，but when substrates content increased a certain amount，removal rates would not be changed.The ammonium nitrogen adsorption of three substrates existed thresholds by the change of pH；whether thresholds rise or fall，the adsorption performance would be decreased.