Abstract:A set of cold-state Circulating Fluid-bed(CFB) with 3 m height has been set up in the laboratory,where the particle size distribution tests have been carried out.The purposes of the tests on main bed pressure distribution are reflecting the movement of the particles inside the bed and the retained amount of the solid particles by measuring the pressures of various heights inside the main bed under various volumes of air blew.The close correlations among the loads of materials and volume of air and the circulating amount of materials can be concluded from the tests on circulating amount of materials.Furthermore,the loop seal,one of the most significant parts of the CFB has been studied in details.