Measurements of CO gasification kinetics of coal chars at temperatures of 1273-1873 K were conducted by using a bench-scale fluidized bed reactor (FBR) made of alumina. The gasification rates of chars carbonized under both rapid heating and slow heating conditions were measured using a high-volatile bituminous coal and a medium-volatile bituminous coal. The significant difference in reactiving between rapid hearing chars and slow heating chars, and the decrease of char reactivity ai high temperature were discussed.