Abstract: Using the static coal combustion and ash cold sieving experimental method,the attrition rate constants of four kinds of coal ash were measured.It was found that the attrition rate constant of the same coal ash decayed exponentially with increasing particle size, while the attrition rate constants of different kinds of coal ash with the same size were different.The coal ash components were found to cause the above phenomena.By assuming the coal ash mainly composed of metakaolin, quartz, ferric oxide and calcium oxide, the influences and tendency of coal ash components on attrition rate constant were deduced with the gray system theory and neural network.The increase of metakaolin, ferric oxide and calcium oxide contents could increase the attrition rate constant, while the attrition rate constant would decrease with increasing amount of quartz.