Abstract: The main parameters in the control of the preparation mineral polymer using fly ash, as a by-product of coal-fired steam powder plants, is the composition and the content of the amorphous phase in the fly ash. The popular methods to quantitative determination of the amorphous phase were summarized, especially the Rietveld X-ray powder diffraction (XRPD) method and selective chemical treatments, including their principles, merits and demerits, respectively. On the describes of these methods and its applications, the major questions and development directions were put forward, which sorting out the amorphous phase research thoughts and providing the basic direction for the amorphous phase determination of fly ash.