Kinetics of phosphates removal by Municipal Solid Waste Incineration(MSWI) fly ash were investigated with the tests of EDS, XRF and TEM. It was shown that 95% of phosphates was removed by MSWI fly ash in 30min under 303 K. The process was heat intaking process whereas the heat amount required was small. Heavy metals were stabilized during the process and no heavy metals were detected in solution after reaction. Chemical precipitation was the main way of phosphates removal. Ca、Fe、Zn etc. can provide cations for phosphates removal reaction. The macro kinetics of phosphates removal by MSWI fly ash can be represented by the model of sphere internal diffusion control. And internal diffusion process of PO34 and soluble products were the controlling step. The relation between reaction rate of phosphate (X) and reaction time (t) can be represented as 13(1X)2/3+2X=kt; the apparent activation energy was about 10.06kJ / mol .