The Reactivity of corn cob char in CO2has been studied on a thermogravimetric balance to develop a rate equation for the design of biomass gasifiers operating on corn cob char. Experiments in the range of 650-1000°C were conducted with cylindrical shaped pellets of 1 cm diameter having L/D=l. The average porosity of the pellets was 0.5. It was observed that the rate of the CO2/char reaction decreased with increase in temperature from 650-750°C and then increased with temperature upto 1000°C.