The kinetic equation of ball milling of quartz powder was deducted. by grinding quartz experiments in a intermittent ball mill. The results showed that: (1) Conventional first-order kinetic equation which describe the velocity of quartz grinding is not concordant with theory. Dynamics parameters are not constant, but time-related. (2) The kinetic equation of time correction can more clearly express their grinding speed. Fitted regression equation has a more accuracy prediction for the instantaneous concentration of particle size, and obtain the dynamics constants. (3) The grinding speed has a maximum value over time because of the particle size distribution and grading comminution. (4).The time index is not only related with the material nature and conditions of the grinding, but also with the particle size distribution. To predict accurately, the grade range should be narrow. (5). Different grinding time distribution of particles in the ball mill should be measured in the continuous grinding process. The comminution results can be predicted by the kinetic equation mentioned above.