Abstract: The effect of the calcium based organic compounds of the modified dolomite by acetate (MDA), calcium acetate (CA) and calcium propionate (CP) on the release of sulfur dioxide (SO₂) and nitric oxide (NO) during LK-lignite combustion has been investigated on a horizontal tuber furnace. And also, the combustion characteristics of them have been studied in a thermogravimetric analyzer. Calcium based organic compound can suppress the release of SO₂ and NO under the suitable conditions effectively. In the temperature range of 973~1 273 K, the calcium based organic can inhibit the release of SO₂. But when the temperature grows higher, the inhibition effect of the calcium based organic reduces except CA. In the lower temperature range of 973~1 173 K, the calcium based organic promotes the release of NO, but when the temperature is higher than 1 173 K, CA and CP show the inhibition of NO obviously. The inhibition effect of SO₂ and NO by calcium based organic generally increases with the increase of the mole ratio of calcium to sulfur (Ca/S). But when the Ca/S is between 2.0 and 2.5, MDA promotes the release of NO. With adding the calcium based organic to LK-lignite, when the Ca/S is 2.0, the ignition performance of LK-lignite improves, the ignition reduces 10~33 K, but its burn time is slightly lengthened.