Abstract: A new type of gas decontaminant- mixed organic calcium salts was prepared. In a spray drying type entrained flow reactor at the range of 900-1100℃ with the gas composition simulating the industrial boiler condition and the contacting time about 1 s, its capability of SO2 removal and NOx reduction from high temperature gas was compared with other gas cleaners, the effect on its SO2 removal and NOx reduction capability under different gas conditions was determined. The order of sorbent utilization for fast SO2 removal is mixed organic calcium salts > CaAc2 > Ca(OH)2 > CaCO3. Utilization of mixed organic calcium salts for fast NO removal is 6.09%, which is approximately 2.5 times higher than CaAc2 under the same conditions, while both CaCO3 and Ca(OH)2 presented no NO reduction ability essentially. Within this temperature range the sorbent utilization for fast SO2 removal increases with the increase of temperature. With respect to fast NO reduction there exists an optimal temperature for the utilization of mixed organic calcium saltS and CaAc2 which is approximately 1000℃. Lower O2 concentration is beneficial to both SO2 removal and NO reduction in the O2 concentration range between 2% to 6%. The experimental results revealed that the cleaner sulfation will promote its ability for NO reduction to some extent.