13 kinds of iron ores ( 6 from Australia and 7 from Brazil) were studied on their properties concerning CW ( Combined Water ) decomposition,Fe 2 O 3 decomposition and softening-melting in air atmosphere through the characterization method of TG-DSC ( Thermogravimetry-Differential Scanning Caloremetry) . The experimental results of the Australian ores and Brazilian ores differ in terms of the initial temperature,temperature range and endothermic amount of CW decomposition,and besides,the content of CW. It is estimated that for every percent increase of CW content in sintering raw material,the extra thermal amount absorbed in the process is about 1. 83 × 10 4 kJ,which equals to the thermal capacity of 0. 625 kg of standard coal burning up completely. As to the decomposition of Fe 2 O 3 ,the initial temperatures, terminal temperatures and temperature ranges of the Australian and Brazilian ores are quite close. However,the endothermic amount of Fe 2 O 3 decomposition of the two turns out rather different: the endothermic capacity of Fe 2 O 3 decomposition of the Australian ores is greater than that of the Brazilian ores. Furthermore,the liquid amount generated in the softening-melting process is closely related to the SiO 2 content in iron ore. The higher SiO 2 content the ore contains, the more liquid volume it will generate in the softening-melting process of iron ore. 13 kinds of iron ores (6 from Australia and 7 from Brazil) were studied on their properties concerning CW (Combined Water) decomposition, Fe 2 O 3 decomposition and softening-melting in air atmosphere through the characterization method of TG-DSC (Thermogravimetry- Differential Scanning Caloremetry). The experimental results of the Australian ores and Brazilian ores differ in terms of the initial temperature, temperature range and endothermic amount of CW decomposition, and besides, the content of CW. It is estimated that for every percent increase of CW content in sintering raw material, the extra thermal amount absorbed in the process is about 1. 83 × 10 4 kJ, which equals to the thermal capacity of 0. 625 kg of standard coal burning up completely. As to the decomposition of Fe 2 O 3, the initial temperatures, terminal temperatures and temperature ranges of the Australian and Brazilian ores are quite close. However, the endothermic amount of Fe 2 O 3 decomposition of the two turns out rather different: the endothermic capacity of Fe 2 O 3 decomposition of the Australian ores is greater than that of the Brazilian ores. The liquid amount generated in the softening-melting process is closely related to the SiO 2 content in iron ore. higher SiO 2 content the ore contains, the more liquid volume it will generate in the softening-melting process of iron ore.