SO2 release and removal were studied under both the air and oxy-fuel combustion conditions using an anthracite coal from the Jincheng mine in China on a bench-scale fluidized bed combustor (FBC). Special attention was paid to the effects of the combustion atmosphere, 02 concentration, bed temperature, and limestone addition. The released amount of SO2 was clearly higher under 30% 02/70% CO2 than that of the air atmosphere. As the O2 concentration in O2/CO2 mixture increased from 21% to 40%, the released amount of SO2 increased significantly, but then it decreased when the 02 concentration increased up to 50%. The bed temperature from 860 to 920 ℃ has no obvious influence on the the SO2 release but shows a strong influence on the desulfurization with limestone in both oxy-fuel and air conditions. The maximum SO2 removal efficiency appears to be at 880 to 900 ℃ for both the air and oxy-fuel combustion conditions.