Abstract: Urban waste incinerator slag showed good performance in dephosphorization. When initial phosphate concentration was less than 200 mg/L, the dephosphorization rate was nearly 100%, and the figure was nearly 60% at initial concentration of 800 mg/L.Langmuir and Freundlich isotherms were found to fit the data of phosphorus adsorption onto incinerator slag well at a significant level.And phosphorus adsorption was best described by the Langmuir model. Based on the Langmuir model, the maximum phosphorus adsorption capacities of incinerator slag was 26 162 mg/kg. The capacity of phosphorus adsorption was not affected by pH value, and it had a lower desorbility rate, and the heavy metal ion concentrations of the leachate of the incinerator slag were low. The results showed that urban waste incinerator slag was a good choice for removing phosphorus from aqueous solution.