The utilization of cattle manure as a blended fuel of pulverized coal fired plant has advantage to both solve waste disposal problems and comply with Renewable Portfolio Standard (RPS) law in Korea. Combustion possibility of cattle manure as a renewable biomass fuel was investigated by thermogravimetric analysis (TGA), 100 kg/h test furnace and ignition temperature (IT) tester through blending of cattle manure to design coal, Carbo bituminous coal. This study included the fuel characteristics (chemical composition, grandability), combustion reactivities (activation energy, kinetic rate constant, ignition temperature, temperature distribution in furnace, combustion efficiency) and slagging characteristics (mineral composition, fusion temperature, slag deposition rate, crystals formation). Thermogravimetric analyses (TGA) performed on Carbo coal, cattle manure, 2.5-40% Blends of cattle manure reveal that cattle manure will start devolatilization at 178 degrees C which is about 78 degrees C lower than 256 degrees C of Carbo coal. Activation energy and kinetic rate constant of Carbo coal were 34.7478 kJ/mol and 53,284 s(-1) whereas those of cattle manure were 9.6935 kJ/mol and 319,038 s(-1). In the cases of 5 and 20% Blends, the activation energies calculated was 23.8714 and 16.4051 kJ/mol, respectively. The activation energy of samples decreased and combustion rate constant was greatly increased with increasing the blending ratio of cattle manure. The experiments of various Blends at 100 kg/h furnace showed that the combustible matters of more than 99.21% burns more completely in the boiler, due to the high surface area, oxygen functional groups (C-O, C = O, and O-C = O) and volatile matter contents in cattle manure. It showed that combustion starting temperature is lowered, the start-up speed is fast, and slag deposit rate on the nearest probes from burner is increased with increasing the blending ratio of cattle manure. The 20% Blends resulted in almost 22 times the slag deposition rate on the nearest probes from burner compared to Carbo coal and ash deposits on probes tubes that were more difficult to remove than other deposits. The increased slagging behavior with blends is probably due to the higher ash loading and alkali mineral composition of cattle manure. Although cattle manure has the high combustion efficiency, it was not appropriate as a single pulverized fuel of a coal fired plant because its Hardgrove grindability index (HGI), ignition temperature (IT) and initial deformation temperature (IDT) of about 35,232 and 1,100 degrees C were too low to cause the shutdown, the spontaneous ignition at pulverizer, and the slagging in furnace. It was therefore proposed that the combustion of blends of cattle manure with less than 10% was the most appropriate for the prevention of pulverizing troubles, slagging and spontaneous ignition at the pulverized coal fired boilers, and, has the excellent combustion efficiency.