The different kinds of circulating fluid bed (CFB) fly ashes from Yuguang gangue－fried power plant in Shanxi Province were studied. According to the different thermal systems and methods of desulfurization of CFB boiler, CFB fly ashes could be divided into 3 types: high temperature and high calcium type (F1), low temperature and low calcium type (F2) and low temperature and high calcium type (XF2). The properties of different kinds of CFB ashes were investigated based on X－ray diffraction, water demand ratio, activity index and compatibility with admixtures. The results show that the number of crystal species of F1 is the most, but the content of amorphous state is the lest; Three types of CFB fly ashes that have not been grinded have high water demand ratio and low activity index, the water demand ratio can be 100% when the specific surface area of fly ash is 600m²/kg; The order of activity index is: XF2 > F2 > F1, and the activity index of F2 and XF2 can be higher than 95%. The conformability between 3 types CFB fly ashes and super plasticizers is well, but the conformability is bad with naphthalene water reducer.