Abstract: The effectiveness of classical sphericity and Krumbein sphericity was compared to discribe chip-shaped fossil fuel, and the influence of sphericity on fiuidization characteristics was studied. Some special pheno-mina in a 50 MW circulating fluidized bed boiler using an anthracit with Krumbein sphericities of 0.2-0.4 were discussed such as obvious fluctuations of dense phase temperature and furnace pressure as well as draining cold ash during operation, which can be explained by particle mophology.