Selecting bituminous coal with average particle size of 0.82 mm as bed material and investigating the influence of the moisture of coal (namely,moisture content of materials) on its flow characteristics in a fluidized bed experiment rig,the relationship curves of fluidizing velocity vs bed height and bed pressure drop were drawn and analyzed.The results show that the critical fluidizing velocity of the coal is 0.3~0.4 m/s;compared with low moisture coal material (moisture content of the coal is 12.4%~13.7%),the critical fluidizing velocity of high moisture coal material (moisture content of the coal is 16.3%~17.8%) increases by 20%,namely,high moisture content is bad for the fluidization of coal;even the slugging phenomenon a high moisture coal may appear in the process of fluidization,which worsens the fluidization.Therefore,the moisture content of coal material should be controlled under 14 %.