Pressurized fluidized bed combustion technology is one of the major technical approaches for coal-fired gas-steam combined cycle power generation. In this technology the coal water mixture fuel pumping technology is used to make fuel preparation and feed system simple, clean and good operation. A test rig of the pump and pipework system has been established in Zhejiang University. In this paper the stability and rheological properties of 0∼6mm Xuzhou coal water paste of different size distribution and water content is described. In need of sulfur retention in the PFBC, the variables of the stability and rheological properties after mixing limestone is collected in the coal-limestone-water paste pumping tests. The rheological parameter of Xuzhou coal from test rig will be used S for directed extrapolation in order to assist in the development of design information of large-commercial coal water paste fuel feed system for PFBC applications.