Abstract: The cold-modeling study conducted on a lime circulating fast-bed fluidized reactor system designed with a gas velocity of up to 2 m/s is described.Through studies on the characteristics of the lime particles and its fluidizing and wearing behaviors,in combination with mathematic derivation,a steady-state fluid-bed particle model has been established.Using this model,when the amount of the feed and bed discharge as well as the lime feed particle size distribution have been given,the steady-state bed inventory and its particle size distribution can be predicted.These data will provide basic information for the study of reaction kinetics and enhance the development and industrial application of this novel technology.