Abstract: The authors apply the ISC3 model to simulate the atmospheric environmental impact of Beijing Jingfeng Heat Power Ltd.before and after using electron beam ammonia flue gas desulfurization(EA-FGD).It is shown that western Fengtai and northern Fangshan are the main zones impacted by air pollutants emitted by the plant and some places in the south of Shijingshan and Mentougou are also impacted by the plant,while the impact on old districts of the city is slight.The maximal annually averaged mass concentration of SO_-2 is 6.10 μg/m 3,which is 10.2% of the Class Ⅱ standard.The maximal annually averaged mass conentration of NO_x is 4.27 μg/m 3,which is 5.3% of the Class Ⅱ standard.After using EA-FGD,under the coal sulfur content of 0.79%,2% and 0.5%,the maximal annually averaged mass concentration of SO_-2 will respectively decrease to 0.86,2.17 and 0.55 μg/m 3,or 86%,64% and 91% less than the current values.The maximal annually averaged mass concnetration of NO_x will decrease 3.42 μg/m 3, which is 20% less than the current value.