A batch small-scale fluidized bed was placed in a pressure vessel to measure CO2 gasification rate of coal char under almost same conditions as in the entrained bed coal gasifiers under development in Japan. This apparatus allowed the rate to be measured under various conditions of CO2 concentration, temperature up to 1773 K and pressure up to 0.8 MPa for char produced at high heating rate. without cooling of the produced char. The rate increased with increased total pressure at constant CO2 concentration as well as with increased concentration at constant total pressure. Thus the gasification rate at a given temperature and its time variation of the char from the coal used in the present study were affected only by the partial pressure of CO2 regardless of the total pressure and CO2 concentration.