This paper presents a dynamic model for a closed-circuit grinding system composed of a ball mill and a separator to represent dynamic behavior of the system especially taking special account of balances of mass and surface of materials at each point in the system. In this model, the transfer function expressing the transporting characteristics inside the ball mill and the grinding kinetics by Andreev＇s formula are obtained and confirmed with several experiments. The dynamics of the system are analyzed with digital simulation using several parameters which have been derived from the experiments. The authors also present a control method composed of a mill load control loop, product fineness control loop and non-interactive calculation part for stable operation of the system and improvement of grinding performance. The effectiveness of this control method is reported with the simulation results and the measurement results of an actual clinker grinding plant.