Abstract: The thermal stability of mercury in Jincheng (JC) coal was studied with TPD-AFS system. An Attempt was made to identify the occurrence of the forms of mercury in JC coal according to its thermal stability. The mercury released at 200℃～300℃ is associated with the sulphate minerals that can be leached by HCl and decomposed at lower temperature. The part of mercury released at 300℃～600℃ is associated with pyrite that can be leached by HNO₃, while a part of mercury is associated with the organic matters in JC coal. The mercury released at 900℃～1200℃ is associated with silicate minerals that can be leached by HF and decomposed at higher temperature. In general, the most of mercury in JC coal associated with minerals and a small fraction of mercury associated with organic matters in coal.