Abstract: Based on the thermal activation theory and curvature-driven mechanism, a 2D cellular automaton (CA) model with different state transition rules was built according to previous cellular automata models. The validity of the model was proved by the shrinking of circular grains. The grain growth was simulated by this model, the microstructure evolution and the kinetics curves of grain growth were obtained, and the distribution of grain size and grain boundary was analyzed. The results indicate that the grain growth is a process of big grain consuming small grain, and the stable grain should be a regular hexagon with rectilinear grain boundary. The growth exponent equals 0.481 close to the theoretical value. The grain size and side distributions keep unchanged with time. The simulation results by the present CA model accord with relative theory and results of other researchers.