Abstract: In order to understand existent regularity of aluminum in high-alumina fly ash of Shanyin power plant in Shanxi province,taken high-alumina fly ash as sample,existent regularity of aluminum in it is analyzed on the basis of this regularity in unburned coal. The result shows that abundant aluminum minerals exist in unburned coal,such as kaolinite; aluminum in fly ash exists as unformed aluminum oxide reaching up to 32. 42%,while this percentage less than that of aluminum-silica. Meanwhile,the aluminum has same regularity in different particle size of fly ash so that it is difficult to extract aluminum by Bayer process or physical ore beneficiation. Trying to find a new way to extract aluminum from this fly ash is based on different reactivity of aluminum and silicon.